Exam Review Day 2 Active Transport- movement across the cell membrane that requires energy ATP Passive Transport- movement across the cell membrane using a protein channel Diffusion- movement from high to low concentration. Across a concentration gradient Osmosis- diffusion of water Semipermeable membranes- cell membranes that controls the passage of materials in and out of cell

Cell Membrane The Cell Membrane regulates what enters and leaves the cell. It also provides protection and suport. It is often described as the “fluid mosaic model” Composed of a Lipid Bilayer. Oxygen and Carbon Dioxide pass through this layer. Protein Channels allow large molecules to move across the membrane library.thinkquest.org/.../cell_membrane.gif

Diffusion Molecules are in constant motion Diffusion is the movement of molecules from an area of high concentration to low concentration. Diffusion does not require the cell to use energy. Diffusion

Osmosis Osmosis is the diffusion of water through a selectively permeable membrane. This does not require energy.

Active Transport Active transport is the movement of molecules against the concentration ( from areas of low concentration to high concentration). This requires energy from the cell.

What Are Enzymes? Proteins but NOT all proteins are enzymesAll enzymes are Proteins but NOT all proteins are enzymes CatalystAct as Catalyst to speed up chemical reactions Not permanentlyNot permanently changed in the process (reusable)

Parts of an Enzyme Reaction The Enzyme provides a site for the reaction to occur. Active Site The reactants, or compounds to be broken or put together, are called the Substrate. The combination of the enzyme and the substrate during the chemical reaction is called the Enzyme- Substrate Complex

Enzymes enzyme

Cellular Respiration Glucose + oxygen -> yields -> carbon dioxide + water and ATP A glucose molecule is broken down into useable energy, in the form of ATP. The mitochondria is the site of aerobic cellular respiration The cytoplasm of a cell is the site of anerobic respiration

Cellular Respiration- Anaerobic Anaerobic- Without oxygen. Takes place in the cytoplasm of the cell. Yeast- alcohol fermentation- alcohol, carbon dioxide and 2 ATP molecules. Bacteria and muscles- lactic acid and 2 ATP molecules Anaerobic respiration uses 1 glucose molecule and makes only 2 ATP molecules.

Cellular Respiration- Aerobic Aerobic respiration takes place in the mitochondria of the cell. From one glucose molecule the mitochondria makes 36 ATP molecules of energy and releases carbon dioxide and water. This is the most efficient use of the glucose molecule. The ATP molecules are used by the cell for work.

Photosynthesis Energy from the sun +water + carbon dioxide  glucose + oxygen + water Light energy comes from the sun and is the original source of all energy on the planet. Plants take in carbon dioxide from the atmosphere Water is taken in by the roots and travels to the leaf and finally the chloroplasts.

Photosynthesis Light Intensity affects photosynthesis. The more light- more photosynthesis takes place Light Color Plants use blue and red light for photosynthesis Amounts of CO2 present controls the rate of photosynthesis

Photosynthesis Plants use wavelengths of light to photosynthesis. Blue and Red wavelengths are used by plants. Green light, 550 nm on the spectrum is not used

Photosynthesis Plants use the glucose they produced for energy during cellular respiration. Plants store the glucose in large macromolecules for later energy use- Starch. Plants use the glucose to make macromolecules of cellulose for structure.

Carbon Cycle The products of photosynthesis are the reactants for cellular respiration. Energy is converted to chemical energy- glucose, in photosynthesis. Cellular respiration converts the energy in glucose into ATP molecules of energy Plants store the carbon in the glucose molecule. Carbon dioxide is in the atmosphere.

DNA- double helix

Protein Synthesis Transcription- DNA copied to mRNA. This occurs in the nucleus. A-U C-G Translation- mRNA goes to the ribosomes and is translated into proteins. tRNA brings the amino acids to the ribosome to be made into proteins. DNA to m

DNA- tacaatgcgact

Mitosis Mitosis – The division of a cell nucleus to make two identical daughter cells. There are 4 divisions of Mitosis. Prophase Metaphase Anaphase Telophase And finally Cytokinesis, where the cell separates into two new identical cells.

Meiosis Similar in many ways to mitosisSimilar in many ways to mitosis Several differences howeverSeveral differences however –Involves 2 cell divisions –Results in 4 cells with 1/2 the normal genetic information. Vocabulary:Vocabulary: –Diploid (2N) - Normal amount of genetic material –Haploid (N) - 1/2 the genetic material. Meiosis results in the formation of haploid cells.Meiosis results in the formation of haploid cells. –In Humans, these are the Ova (egg) and sperm. Meiosis occurs in 2 phases: Meiosis 1 & Meiosis 2Meiosis occurs in 2 phases: Meiosis 1 & Meiosis 2

Overview of Meiosis meiosis animation meiosis animation meiosis animation

Crossing Over Segments of homologous chromosomes break and reform at similar locations.Segments of homologous chromosomes break and reform at similar locations. Results in new genetic combinations of offspring.Results in new genetic combinations of offspring. This is the main advantage of sexual reproductionThis is the main advantage of sexual reproduction

MitosisMeiosis Number of divisions 12 Number of daughter cells 24 Genetically identical? YesNo Chromosome # Same as parent Half of parent Where Somatic or Body cells Germ cells- or Sex Cells When Throughout life At sexual maturity Role Growth and repair Sexual reproduction Comparison of Divisions

Definitions  Alleles - two forms of a gene (dominant & recessive)  Dominant - stronger of two genes expressed in the hybrid; represented by a capital letter (R)  Recessive - gene that shows up less often in a cross; represented by a lowercase letter (r)  Phenotype - the physical feature resulting from a genotype (e.g. red, white)  Genotype - gene combination for a trait (e.g. RR, Rr, rr)  Homozygous RR rr  Heterozygous Rr

Trait: Tall vs short plantsTrait: Tall vs short plants Alleles: T- tallt-shortAlleles: T- tallt-short Cross: Tall plants x Tall PlantsCross: Tall plants x Tall Plants Tt x TtTt x Tt Monohybrid Cross T t tT TT ttTt Genotype:TT, Tt, tt Genotype: TT, Tt, tt PhenotypeTall and short Phenotype: Tall and short G.Ratio:1:2:1 G.Ratio: 1:2:1 P.Ratio: 3:1

Questions omit Mr. Jones could have AA or AO Blood More than one gene controls the trait. Ex. Height and skin color in humans.

DNA electrophoresis

Recombinant DNA Used to produce human insulin using bacteria