Biology I EOC Review

State the 3 tenets of the Cell Theory All organisms are composed of cells. The cell is the basic unit of any organism. Cells come from other cells.

Compare and contrast prokaryotic and eukaryotic cells Prokaryotes have no membrane bound organelles, including a nucleus (pro=before, karyo=nucleus) Eukaryotes have membrane bound organelles (nucleus, mitchondria, ER, vacuoles, etc.) (eu=true) All cells have a cell membrane, cytoplasm, and ribosomes

Kingdoms Archaea and Bacteria are the only prokaryotes All other cells (Kingdoms Protista, Fungi, Plantae, and Animalia) are eukaryotes

Identify basic cell organelles, giving their structure and function Nucleus – contains DNA, large, usually found in cell’s center, surrounded by a nuclear membrane

Mitochondria – site of Krebs cycle and electron transport of cell respiration; bulk of ATP made here to supply the cell with energy

A Mitochondrion Outer membrane, folded inner membrane (cristae), fluid called matrix

Chloroplast – site of photosynthesis; contains chlorophyll along with accessory pigments that absorb the energy from the sun to convert carbon dioxide and water into sugar

A Chloroplast Outer membrane, inner membrane organized in flattened sacs (thylakoids), surrounded by fluid called stroma

Lysosome – membrane bound; contains digestive enzymes for breaking down cells and molecules Vacuoles – storage compartments; membrane bound; contain food, water, or waste; plant cells have large water vacuoles and animals have small ones

Ribosomes – site of protein synthesis; very small (relatively speaking!) and numerous; often found on the surface of ER

Endoplasmic Reticulum (ER)- membrane bound tubes that transport materials; rough if ribosomes are attached, smooth without ribosomes

Golgi – membrane bound, flattened, stacked, sacs; modifies, collects, packages, and distributes molecules

Cilia and Flagella – small, hairlike extensions on the outside of cells; usually used for locomotion

Cell membrane (plasma membrane) – cell structure that encloses the cell and regulates the passage of materials into and out of the cell; protects and supports the cell

Cell Wall – outside cell membrane; provides support; plants, bacteria, fungi, and some protists have cell walls

Cytoplasm – jelly-like material; moves large particles around in cell

Locate and identify the organelles from a drawing or model of a cell

Classify a cell as a plant or an animal cell Plant cells – have cell walls, a large water vacuole, and chloroplasts Animal cells – no cell walls, can have cilia and/or flagella

Which is the plant and which is the animal cell? How do you know?

Explain cell differentiation as the basis for the hierarchical organization of multicellular organisms A fertilized egg (zygote) divides to make different kinds of cells with different structures and functions As cells divide, certain genes are activated or “turned on” and some are deactivated or “turned off” so the cells become different kinds of cells (differentiation)

Stem cells are unspecialized cells that can differentiate; embryonic stem cells are found in embryos; adult stem cells are found in adults, such as cells in bone marrow that differentiate into different types of blood cells

A group of like cells make up a tissue Groups of different tissues make up an organ Groups of organs make up an organ system cells  tissues  organs  systems

Explain active, passive, and facilitated transport Passive transport – materials move from higher to lower concentrations using their own energy; this movement is downhill; the membrane must be permeable to the particle

Active transport - materials are moved from lower to higher concentrations using the cell’s energy; this movement is uphill or against the concentration gradient; for example, when glucose is moved into liver cells even if the concentration is higher in the liver cells than the surrounding blood the liver cells use their own energy (ATP)

Active Transport Animation place/biocoach/biomembrane1/diffusion.ht ml place/biocoach/biomembrane1/diffusion.ht ml

Some particles require proteins (ion channels) to diffuse through; this is called facilitated diffusion

DIFFUSION IS PASSIVE IF PARTICLES ARE MOVING FROM A HIGHER TO LOWER CONCENTRATION (DOWN THE CONCENTRATION GRADIENT) EVEN IF IT IS FACILITATED DIFFUSION!!!!! FACILITATED DIFFUSION ISN’T NECESSARILY ACTIVE!!!! (It’s only active if particles are going “uphill” or from a lower to higher concentration)

Hypotonic – solute concentration is low (water concentration is high) Hypertonic – solute concentration is high (water concentration is low) Isotonic – solute concentrations are equal (at equilibrium) (TONIC MEANS SOLUTE – NOT WATER!!!)

Water goes Out of hypOtonic areas and entERs hypERtonic areas

Animation showing cytolysis (bursting) and plasmolysis (shrinking) of a human red blood cell

Cytolysis – cells taking in too much water (plants prevent this by the cell wall)

Plasmolysis – plants losing too much water

Large Particles are Transported by Vesicles

Large Amounts of Materials Get Into Cells by Endocytosis and exit by Exocytosis

Explain the cell cycle to include cytokinesis and mitosis, G 1, S, and G 2, and cytokinesis

G 1 – cell grows and matures S – DNA replicates G 2 – cell prepares for mitosis by making proteins used in the division Mitosis – cell divides DNA Cytokinesis – cytoplasm and other organelles are divided

Structure of a double-stranded chromosome

Prophase – nuclear membrane breaks down; chromatin condenses into chromosomes; centrioles (in animal cells) move to opposite poles; spindle forms and attaches to opposite chromatids

Metaphase – chromosomes line up at the cell’s equator (metaphase plate)

Anaphase – spindle pulls sister chromatids apart to opposite poles (dividing at the centromere)

Telophase – nuclear membrane reforms around each set of DNA; chromosomes once again become chromatin; spindle fibers break down; overlaps with cytokinesis

Cytokinesis – cell divides into two daughter cells; in animal cells, cleavage occurs (creates a cleavage furrow) when the cell pinches in to form 2 cells; in plant cells, a cell plate forms in the cell’s center which will later from a new cell wall

Discuss cancer as cell division out of control Tumor cells have lost their ability to control their cell division; caused by carcinogens (environmental factors), mutations, or an unknown cause

Signals from inside the cell (internal signals) and from outside the cell (external signals) turn cell division off and on Cells divide when they are loosely packed together and stop dividing when they are touching other cells Checkpoints are places in the cell cycle where there is either a STOP signal or a GO signal

Cells of the immune system can sometimes detect cancer cells and destroy them A malignant tumor invades tissues and keeps them from performing their function; it can also spread (metastasize) A benign tumor doesn’t impair tissue or organ function (usually) and doesn’t metastasize

Explain that enzymes lower activation energy. Enzymes lower activation energy (energy required to start a chemical reaction), causing reactions to proceed faster Enzymes are catalysts – they speed up chemical reactions, but aren’t changed themselves

Reaction With and Without an Enzyme

A Substrate Fits into the Active Site of an Enzyme Molecule

An Enzyme and its Substrate Fitting into the Active Site

Enzymes are affected by pH, temperature, substrate concentration, and enzyme concentration

Most Enzymes Can’t Function if it’s too Hot or too Cold

Most Enzymes Function in the Neutral Zone (pH of 7)

Buffers are chemicals that regulate pH to maintain homeostasis (keeping the same environment)

HEREDITY Describe the basic structure of the nucleic acids – deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) Nucleic acids are composed of nucleotides Nitrogen base + sugar + phosphate

Nucleotides bond in long chains to form RNA and DNA

State the 3 structural differences between RNA and DNA RNA contains ribose; DNA contains deoxyribose DNA contains adenine (A), thymine (T), guanine (G), and cytosine (C) ; RNA contains A, G, C, and uracil (U) DNA is double stranded (double helix); RNA is single stranded (single helix)

Summarize the relationship between DNA, genes, and chromosomes Chromosome – structure in the nucleus consisting of one long thread of DNA that is tightly coiled around special proteins called histones DNA – molecule composed of nucleotides, providing the blueprint for the making of proteins

Gene – segment of DNA with the genetic code for making one protein Chromosomes are made of DNA (and protein), in which small segments code for the amino acid sequence of a protein

Summarize DNA Replication

Enzyme unwinds DNA Enzymes breaks hydrogen bonds holding pairs bases together Another enzyme bonds new DNA nucleotides to each strand Each identical DNA molecule has ½ the original strand and ½ of a new strand

Summarize transcription Transcription is the synthesis of RNA Transcription occurs in the nucleus

Transcription

The two complementary strands of DNA separate by breaking the hydrogen bonds between paired bases An enzyme bonds RNA nucleotides to one DNA strand T bonds to G and A (on DNA) bonds to U (on RNA)

Summarize the steps of translation Translation – the making of protein Proteins are made by forming peptide bonds between amino acids in long chains

Amino acids bond by making peptide bonds

The Genetic Code

Translation begins with mRNA attaching to a ribosome The first codon on mRNA is read (usually AUG) and the tRNA with the codon’s corresponding anticodon brings an amino acid to the ribosome The codon on mRNA is complementary to the anticodon on tRNA bond

A second codon is read and a second tRNA, also carrying the corresponding amino acid, attaches to the codon The two amino acids bond together The first tRNA breaks away from the mRNA and the mRNA slides down to read the next codon

This continues until one of the stop codons is reached The long chain of amino acids is a polypeptide Once the polypeptide folds up on itself and is processed by the Golgi, the protein is complete

Explain how our study of heredity is used in modern genetics Genetic engineering – putting genes from one organism into another; can create drought resistant plants, higher crop yields, medicine like human insulin, pest-resistant plants

The Human Genome Project’s goal was to sequence human DNA instead of finding genes one at a time; project completed in 2003

Gene maps show where genes are located on chromosomes

Clones are genetic copies; it may occur naturally (identical twins) or by human intervention; cloning could produce organs for transplant or save endangered species Gene mutations could be cured through gene therapy, in which corrected versions of genes are inserted (sickle cell, Tay- Sacs, cystic fibrosis)

Stem cells are undifferentiated cells; research could lead to cures for diseases or ways to replaced damaged body parts; stem cells can be adult or embryonic Selective breeding is artificially selecting organisms to breed for traits we want; all domesticated plants and animals were created by selective breeding; the disadvantage is the descendants come from a few ancestors that may have had undesirable genes (for ex: deafness is common in dalmatians)

Hybridization is another type of selective breeding in which two closely related species are bred; the offspring can often have the best traits of both; donkeys and horses mate to have mules

Summarize the steps of meiosis Meiosis is very similar to mitosis; exceptions: in meiosis, the daughter cells divide twice instead of once, crossing over occurs during prophase I (mixes up genes), chromatids don’t separate until anaphase II, all 4 daughter cells are genetically different, cells are haploid (1 chromosome per pair)

Summarize Mendel’s Genetics Principles Principle of Dominance and Recessiveness – some genes can hide or mask others Law of Segregation – Mendel’s genetics principle that states that genes in pairs separate during gamete formation and gene pairs are reformed during fertilization Law of Independent Assortment – genes are inherited separately and that creates a variety in a population

Work problems using Punnett squares to illustrate the following inheritance patterns: monohybrids, dihybrids, sex- linked, multiple alleles, polygenic traits, codominance, and incomplete dominance Monohybrid crosses – Punnett squares showing one trait at a time

Monohybrid Cross

Dihybrid Crosses – Punnett squares showing 2 traits; 16 square Punnett squares

On a dihybrid cross, if both parents are doubly heterozygous, the ratio in the offspring is 9:3:3:1

Sex-linked – genes found on the sex chromosomes; in humans, females have 2 X chromsomes (2 genes) and males have 1 X chromosome and 2 Y (they have 1 gene) Example: hemophilia and Duchenne muscular dystrophy

Multiple Alleles – more than 2 alleles (forms of a gene) Example: blood types in humans; there are 3 alleles instead of 2; A gene, B gene, and O gene

Codominance – 2 different alleles that are both dominant, so in a heterozygous gene pair, both traits show up Example: A and B genes in human blood type; if a person is AB genotype, they make both A and B proteins and have blood type AB

Incomplete Dominance – heterozygous genotype gives a different phenotype Example: red and white genes in Japanese four o’clocks; a red gene paired with a white gene makes a pink flower

Polygenic Traits – traits controlled by more than one pair of genes; example: human skin color and human height

Explain gene linkage Discovered after Mendel; states that if genes are on the same chromosome and located close together, they are often inherited together Example: red hair and freckles in people Seems to violate Mendel’s independent principle, but as long as genes are on different chromosomes or found far apart on the same chromosome, his principle holds true

Give examples of both chromosomal and gene mutations Chromosomal mutations affect a large part of a chromosome and therefore all of the genes on that section of the chromosome Gene mutations only affect one gene and therefore, one protein

Deletion mutations – deletion of a section of chromosome or one small section of a gene Example: cystic fibrosis is a deletion mutation in which 3 bases are deleted from a gene for a transport protein for Cl -

Substitution mutations – one base gets substituted for another one Example: in sickle cell, one base substitution in the gene for hemoglobin causes abnormally shaped red blood cells

Nondisjunction mutations – chromatids or homologs fail to separate during meiosis; example: Down’s syndrome is caused from an extra 21 st chromosome

Discuss possible causes of mutations to include natural (random) and environmentally induced. Mutations can occur naturally during DNA replication, cell division, or caused by naturally occurring substances in the environment (radon from the ground, UV radiation from the sun, for example).

Mutations can also be caused by manmade or synthetic substances, such as Agent Orange, biological warfare chemicals, pesticides, and radiation.

Explain the difference between a mutation in a somatic cell and one in a sex cell. Somatic mutations take place in cells of the body (skin, muscle, etc.) and are not passed on to offspring Germ cell mutations occur in sex cells and are passed from parent to offspring

Identify some common mutations Sickle cell anemia – mutation in gene for hemoglobin; causes abnormally shaped red blood cells; autosomal (not found on sex chromosomes) recessive

Tay-Sachs – mutation in a gene for an enzyme that functions in the breakdown of a protein in neurons; autosomal recessive Cystic fibrosis – mutation in a Cl - transport protein; autosomal recessive Hemophilia – mutation in gene for blood clotting; sex-linked

Huntington’s – progressive nervous deterioration; symptoms don’t occur until middle age; inherited as an autosomal dominant gene

Albinism – mutated gene for pigments; white hair; white skin; usually pink eyes

Mutations caused by nondisjunction Down’s – extra 21 st chromosome Klinefelter’s – extra X chromosome; males; XXY Turner’s – missing X chromosome; females; XO

Interpret pedigrees to determine how a trait is inherited in a family

How is this trait inherited?

EVOLUTION Define evolution Changes that have transformed life on Earth from the earliest beginnings to the diversity of organisms in the world today

Explain factors that increase genetic variability in a population Sexual reproduction causes an increase in genetic variability by recombining genes from two different parents Mutations increase genetic variability to creating new DNA base sequences

Crossing over increases genetic variability by causing a wider diversity in gametes Genetic drift – random change in a population Gene flow – movement of genes into or out of the population

Summarize the Hardy-Weinberg Principle Evolution can be measured by determining gene frequency (how often does a gene appear in a population); if it changes, evolution has taken place. If there is no change in the gene frequency of a population, it is in genetic equilibrium

To maintain genetic equilibrium, a population must meet 5 conditions (1) Population is large. (2) No movement into or out of the population (3) random mating (4) no mutations (5) no natural selection (all genotypes have equal chance of survival)

Explain the process of speciation Speciation is the process of forming a new species New species form when organisms in the population are isolated so that the new population is prevented from reproducing with the original population

Isolation can be: temporal: species can’t interbreed (might breed during different times) behavioral: courtship behaviors keep species separated geographic: islands, bodies of water, mountain ranges, etc. separate species

Summarize patterns of evolution Gradualism – species change over long periods of time, such as a gradual trend toward a larger beak or color of fur Punctuated equilibrium – period of abrupt changes after long periods of time with little change

Adaptive radiation (divergent evolution) – a number of different species branch or split off a common ancestor Convergent evolution – evolution among different groups of organisms living in similar environments produce species that are similar in behavior or appearance Coevolution – two or more species living in close proximity change in response to each other

Extinction – elimination of a species when they cannot adapt to a change in the environment Extinction can be (1) gradual – decline in numbers over long periods of time (2) mass extinction – caused by a catastrophic event (such as volcanic eruption, fire, or a meteor hitting the earth)

Define carrying capacity The largest number of individuals in a population that the environment can hold; there’s enough food, space, shelter, water, nutrients, etc. to allow that many individuals to survive Causes a competition among organisms

Graph showing carrying capacity

Distinguish between microevolution and macroevolution. Microevolution is small changes in a population that take place quickly; example: change in color of peppered moths Macroevolution is the accumulation of small changes over a long period of time that can cause speciation

Compare and contrast analogous, homologous, and vestigial structures and their role in determining evolutionary relationships. Analogous structures – structures with the same function, but not of common descent; examples: bird wings and insect wings

Homologous structures – similarity in structure due to common ancestry; example: forelimbs of human, alligator, bat, and gorilla

Vestigial structures – parts of an organism with no apparent function today Example: appendix in humans; pelvic bones in whales; eyes in blind fish that live in dark caves

Explain how fossils provide evidence of change over time. Some organisms leave traces (imprints of skin or leaves, bones, etc.) which provide information about what they looked like, etc. when they lived

Describe how DNA base sequence and amino acid sequences provide evidence of common ancestry and change over time. The number of DNA base sequences and amino acid sequences two organisms have in common demonstrate how closely related they are

For example, humans and dogs have more DNA sequences in common than humans and ferns. The hemoglobin of humans and gorillas have more amino acids in common than humans and frogs.

Discuss how examination of embryological features can provide evidence of common ancestry and change over time. Animal embryos can be examined to identify common structures.

25 week old human embryo

Explain that natural selection is the process responsible for evolution. Organisms produce many more offspring than can survive. Because there is a variety in the population, those more adapted survive and pass those favorable traits to their offspring. “Survival of the fittest”

Explain why traits that do not confer advantage may or may not disappear over time. Recessive genes are always present in a population; example: people with Tay- Sachs die before reaching elementary school age, so they never reproduce; Tay- Sachs children continue to be born because of heterozygous parents (they are carriers and have the recessive gene)

Describe the process by which fossils are formed. Remains are covered by soil that forms into sedimentary rock; insects get trapped in tree sap to make amber; organisms are frozen; imprints are made in wet soil that harden into rock

Discuss the significance of The Origin of Species. Charles Darwin made an excellent argument for evolution caused by natural selection based on the evidence he collected from the Galapagos Islands and it changed the study of evolution.

Name the 6 kingdoms most commonly used for classification and give the basic characteristics of each. Archaea – prokaryotes that live in harsh environments; unicellular Bacteria – prokaryotes; unicellular Protista – mostly unicellular eukaryotes Fungi – mostly multicellular eukaryotes; heterotrophs; nonmobile; cell walls

Plantae – all multicellular eukaryotes; immobile; autotrophs; cell walls Animalia – all multicellular eukaryotes; mobile; heterotrophs; most have nerve cells

Create a phylogenetic tree

ECOLOGY Describe what occurs during the carbon cycle to include the relationships between producers, consumers, decomposers, photosynthesis, and cellular respiration.

Describe what occurs during the nitrogen cycle to include nitrification, ammonification, assimilation, and denitrification.

Describe the role of nitrogen fixing organisms in the nitrogen cycle. Bacteria in the soil take nitrogen from the air and fix it; they combine it with other elements to make nitrates or ammonia that plants that use.

Describe what occurs during the water cycle to include the role of plants and photosynthesis.

Determine that the sun is the ultimate source of energy on Earth. All living things get energy from food; heterotrophs get energy from autotrophs that get their energy from the sun during photosynthesis.

Explain the role of producers and consumers in the ecosystem. Producers undergo photosynthesis and make food for all other organisms. Consumers eat plants or other consumers. This creates food chains and food webs.

A Food Web

Relate the trophic levels in the ecosystem to pyramids of energy, numbers, and biomass.

Pyramids of biomass and energy

Explain the flow of energy within a food chain and why energy transfer is not 100%. Some energy in food is wasted as heat. Not all producers get eaten. Not all of an organism is eaten or digested.

Tell why there are limits to the numbers of consumers in a food chain. As consumers get energy from other consumers, the energy gets less and less, until there isn’t enough energy for survival.

Explain why the producer level contains more biomass/unit area than consumers and why this is necessary. Consumers get energy from producers, so there must be more total mass of producers than any other organisms in a food chain.

Describe how birth and death rates affect population growth. If birth and death rates remain equal, there is zero population growth. If birth rates are high and death rates are low, the population will increase.

If birth rates are low and death rates are high, the population will decrease.

Describe the ways in which human population growth has affected the environment Food shortages Pollution of the environment Spread of diseases Decrease in available clean water Decrease in amount of fertile soil Increase in earth’s temperatures

Reduction of nonrenewable resources (such as oil and coal) Over-consumption of renewable resources

Explain the difference between abiotic and biotic factors. Biotic factors are the living parts of an ecosystem; plants, fungi, bacteria, animals, etc. Abiotic factors are the nonliving parts; nutrients in soil, sunlight, temperature, pH, wind, etc.

Define and describe different types of symbiosis Parasitism – an organisms lives in or on another (the host); ticks feed on dogs, mistletoe feeds on a tree Commensalism – two organisms live together; one is benefited, while the other is neither helped nor harmed; fish live within sea anemone’s tentacles

Mutualism – two organisms live together and they both receive benefit from the relationship; E. coli in the human intestine (human provides water and nourishment for the bacteria and the bacteria produce vitamin K for the human)

Define succession and give explanations for each step in the process

pioneer species – the first plants and animals to grow climax community – the ecosystem present at the end of succession; could be a desert, forest, etc.

primary succession – occurs where no soil exists, such as on volcanic islands, where glaciers melt, etc. secondary succession – succession that occurs when land is disrupted; land that is cleared for farming and abandoned, for example

Explain how human use of fossil fuels has contributed to global warming.

As fossil fuels, such as gasoline, oil, and coal are burned, they produce carbon dioxide that accumulates in the atmosphere, which prevents heat from escaping into space. This is increasing the temperature of the earth.

Explain the effect of CFCs on the destruction of the ozone layer. Chloroflurocarbons destroy the ozone layer that protect the earth from harmful ultraviolet (UV) radiation from the sun

Define acid rain in terms of pH and give sources of acid rain. The pH scale ranges from 0-14, with 7 being neutral. pH values below 7 are acidic, while values above 7 are alkaline or basic. When fossil fuels are burned, sulfur is given off and combines with oxygen to become sulfur dioxide, which is acidic.

ENERGY Define energy. Energy is the ability to do work.

Write the overall equation for photosynthesis and show where each reactant ends up on the product side.

Describe what happens to the excited chlorophyll electrons as they cycle through the photosynthetic process. electrons in chlorophyll a molecules take in energy from light and become excited these electrons jump out of chlorophyll a

some of the energy in these excited electrons are used to produce ATP some of the energy is bonded to NADP to make NADPH; these energized hydrogen electrons are used to make glucose during Calvin cycle (the dark reactions)

Summarize the events of the light and dark reactions.

the dark reactions occur in the stroma of the chloroplast carbon dioxide is taken in ATP from light reactions is used, along with the hydrogen atoms from NADH glucose is produced

Explain why the dark reactions are dependent upon the light reactions In order for glucose to be made during the dark reactions, energy from ATP is required along with energized hydrogen electrons from NADH; ATP and NADH are both produced during the light reactions

State the role of chlorophyll and the chloroplast in the photosynthetic process chlorophyll is necessary to absorb the energy from the sun photosynthesis takes place in the chloroplast; light reactions occur in thylakoids; dark reactions occur in the stroma

Explain the significance of the splitting of water during photosynthesis as electrons get excited and jump out of chlorophyll a, they are replaced by splitting water and getting hydrogen electrons oxygen is given off as a waste product

Write the overall equation for cellular respiration, identifying the reactants and products. C 6 H 12 O 6 + 6O 2  6CO 2 + 6H 2 O reactants products

Distinguish between aerobic and anaerobic respiration, and state the conditions under which each occurs. aerobic respiration requires oxygen anaerobic respiration does not

glycolysis, Kreb’s, and electron transport occur during aerobic respiration only glycolysis occurs during anaerobic respiration the net ATP yield of anaerobic is 2ATP molecules; the net yield of aerobic is 38 ATPs

Describe the role of the mitchondria during in aerobic respiration. Krebs cycle and electron transport take place in the mitochondria

Define glycolysis and tell why it occurs in all organisms. glycolysis is the break down of glucose into two pyruvic acid molecules it occurs in the cytoplasm since glycolysis occurs in both aerobic and anaerobic respiration, it occurs in all organisms

Glycolysis

Differentiate alcohol and lactic acid fermentation. both types of anaerobic respiration pyruvic acid is converted into ethyl alcohol or lactic acid alcohol fermentation occurs in some organisms lactic acid fermentation occurs in aerobes with small amounts of oxygen

Describe the overall process of the Kreb’s cycle all the original glucose is oxidized during Kreb’s CO 2 is produced Excited H electrons bond to NAD to form NADH

Describe what happens during the electron transport chain and chemiosmosis

NADH and FADH 2 molecules give up their energized H electrons the electrons travel down an electron transport chain located in the inner membrane (cristae)

The energy from the H electrons is used to carry hydrogen protons to the other side of the membrane; the protons diffuse back across through ATP synthase which bonds phosphates to ADP to produce ATP The H atoms bond to oxygen to produce water

Explain how the structures of organic molecules are related to their caloric values carbohydrates (sugars) and protein contain about 4 calories per gram (energy found in the H-O bonds) fats contain about 9 calories per gram (more calories due to the H-O bonds present)

Proteins have the same calories as carbohydrates, but are often not used as an energy source; they are digested into amino acids to be used in protein synthesis

Carbohydrates are used as an energy source by the human body first, then lipids Carbohydrates are simple sugars (monosaccharides) or complex sugars (polysaccharides) Carbohydrates are digested and carried through the blood to be used during respiration to make ATP Some carbohydrates can’t be digested (fiber) and stimulate the digestive system

Lipids (fats, oils, and waxes) are composed of glycerol and fatty acids Lipids are used as energy AFTER carbohydrates; also used to make new cell membranes Blood carries the glycerol and fatty acids after digestion

Proteins are composed of amino acids Amino acids contain C, H, O, N, and sometimes S atoms There are 20 different amino acids that bond in a particular sequence to make a protein Proteins make up most of the dry weight of an organism

Proteins can be structural, such as proteins like keratin that make up hair and nails Proteins can transport molecules, such as hemoglobin that carries oxygen Most hormones are proteins, such as insulin that regulates glucose levels in the blood Contractile proteins control movement, such as proteins in muscles Enzymes are proteins

Identify the 3 parts of ATP

The “high energy bonds” are formed between the phosphate groups

Show how ATP is recycled ADP + phosphate group  ATP  When a phosphate group breaks off, energy is released. Energy has to be input to reattach the phosphate group to the adenosine diphosphate (ADP).

The End! RFM 2003, revised 2012