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You Asked for it….. Biology REVIEW.

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1 You Asked for it….. Biology REVIEW

2 biomolecules Building Block Uses Examples Test Carbohydrate
Simple sugars Ready source of energy Glucose Glycogen Cellulose Starch STARCH turns purple in iodine SUGARS react with Benedict’s Solution Protein Amino acids Transport Speed up reactions Immunity Cell communication Enzymes (-ase) Hemoglobin Antibodies Protein hormones (insulin) Reacts with Biuret Solution Lipid Fatty Acids Back up energy source In membrane Fats, oils Leaves oily spot on brown paper bag Nucleic Acid Nucleotide Store and transmit genetic info DNA, RNA DNA stains (methylene blue)

Eukaryotic cells have their DNA surrounded by a membrane.  (They have a nucleus).  Two examples shown are plant cells and animal cells, but fungi and protists are also eukaryotic Notice, plants have chloroplasts (for photosynthesis) and cell walls made of cellulose. Animal cells don't have these parts.  Also, plant cells have a larger vacuole for storage.  Both plants and animals have mitochondria to make ATP. All eukaryotic cells have ribosomes to make protein These cells are more complex than prokaryotic cells. Prokaryotic cells have DNA and ribosomes, but they have no internal membranes! (They don't have a nucleus) They have ribosomes to make proteins These are the simplest cells Examples are bacteria, like those that cause strep throat.

4 The plasma membrane surrounds EVERY cell.
CELL MEMBRANE The plasma membrane surrounds EVERY cell. It is made of lipid and protein It controls what goes in and out of a cell. Associated with HOMEOSTASIS

5 Diffusion Osmosis Active Transport CELL TRANSPORT
Movement from high to low concentration No energy required Osmosis Movement of water from high to low WATER concentration across a membrane Active Transport Movement from LOW concentration to HIGH concentration USES ATP

6 Enzymes are specific for reactions bind to substrate at active site
are not changed in the reaction speed up reactions are made of PROTEIN are reusable

7 Photosynthesis and Respiration
Converts sunlight to chemical energy Converts energy in food (glucose) to ATP Cellular Respiration Takes place in mitochondrion Releases the energy stored in glucose AKA aerobic respiration (NEEDS oxygen)

Requires oxygen Makes A LOT of ATP Produces carbon dioxide and water Happens in mitochondrion Does not use oxygen Makes only 2 ATP Small amount of ATP Also called fermentation YEASTS make ethyl alcohol BACTERIA and MUSCLE CELLS (w/o O2) make LACTIC ACID Happens in cytoplasm (cytosol)


10 Asexual vs Sexual Reproduction
Asexual Reproduction Adds genetic variation Involves meiosis and fertilization TWO parents involved Diploid and haploid cells Creates identical copies (clones) Only involves MITOSIS ONE parent involved Common in bacteria and unicellular protists

11 Mitosis and Meiosis One division Two divisions 2n  2n 2n  n
(same number of chromosomes) Results in 2 genetically identical cells Two divisions 2n  n Half the number of chromosomes Results in 4 DIFFERENT haploid cells Forms gametes (egg and sperm)

12 DNA DNA is a polymer of nucleotides.
A nucleotide is made up of three parts: a sugar, a phosphate and one of four bases In DNA, the bases are A, T, C, and G DNA’s shape is a double helix The two strands are held together by HYDROGEN bonds A binds to T C binds with G

13 DNA Replication Process of DNA copying itself Steps
DNA Unzips (Hydrogen bonds break) Each side acts as a template New DNA nucleotides are added according to base-pairing rules Two new molecules of DNA result – each with one old and one new strand. Happens in INTERPHASE (before mitosis or meiosis)

14 DNA  mRNA  protein Protein Synthesis Made of amino acids
Remember, genes are made of DNA and are in the nucleus Genes (DNA) contain the instruction for making  a protein In transcription, DNA is used to make mRNA in the nucleus mRNA then leaves the nucleus and goes to the ribosome In translation, tRNA then brings amino acids in the proper order to make the protein on the ribosome. DNA  mRNA  protein Made of amino acids

GENES (made of DNA) hold code for protein RNA mRNA is made in nucleus TRANSCRIPTION Remember base pairing rules PROTEIN mRNA goes to ribosome 3 bases on mRNA is a codon – each codon codes for one amino acid tRNA brings the right amino acid to the mRNA Anticodon on tRNA base pairs with codon on mRNA

16 Can you IDENTIFY the parts?
DNA mRNA Nucleus Cytoplasm Ribosome Codon Anticodon tRNA Amino acid Protein (polypeptide)

Be sure to use mRNA You won’t have to memorize this! What amino acid is coded for by the DNA ATA GAG First convert DNA to mRNA ATA GAG UAU CUC UAU = tyr CUC = Leu

18 Genetics We have two genes for each trait – this is our GENOTYPE One gene came from mom, one from dad If the genes are alike, the individual is homozygous (RR, rr) If the genes are different , they are heterozygous (Rr) Some genes are dominant and others are recessive We only show a recessive trait if we have no dominant gene RR and Rr would “look” dominant rr would look recessive This diagram shows the cross between 2 heterozygous purple flowers Cross is: Bb x Bb Notice that 75% are purple and 25% white

19 Sex Linkage Females are XX Males are XY Sex-linked traits are on X chromosome Trait is more common in MALES Examples are colorblindness and hemophilia (blood fails to clot) Males give X chromosomes to their daughters and Y’s to their sons Moms give X’s to both daughters and sons

Four blood types A, B, AB, O Three different alleles: A, B or neither A = AA or AO B = BB or BO AB = AB O = OO Agglutinogen = protein

21 PEDIGREES 4 = Ee (parent 2 had to give an e)
Tracing traits through generations Males are squares Females are circles Horizontal line means married Vertical line means children Filled in circle means the individual HAS the condition Can you identify the genotypes of individuals 4, 7, 12? 4 = Ee (parent 2 had to give an e) 7 = Ee (child is ee, so they had to have one e) 12 = ee (affected with recessive condition)

22 KARYOTYPE XY = male In humans, 22 pair of autosomes
A chart showing arrangement of chromosomes In humans, 22 pair of autosomes 1 pair of sex chromosomes XX = female XY = male Extra chromosomes a result of non-disjunction Chromosome pairs fail to separate in meiosis One example is DOWN SYNDROME (extra 21) Another example is KLINEFELTERS (XXY) 3 21’s = Down Syndrome

23 GENETIC TECHNOLOGY Use gel electrophoresis to compare DNA fragments
DNA FINGERPRINTING TRANSGENIC organisms Use gel electrophoresis to compare DNA fragments IF DNA matches, it’s from the same individual Organisms that have 2 different kinds of DNA Gene cloning Uses bacteria to make human proteins like insulin Evidence points to suspect 2

24 EVOLUTION – change over time
EVIDENCE Natural Selection Fossil evidence Fossils found in sedimentary rock Lower level fossils are older and more PRIMITIVE We can compare fossils to modern organisms Similar structure suggests common ancestor Biochemical evidence DNA and protein similarities suggest common ancestor Credited to Charles Darwin Organisms in populations have variations that can be passed from generation to generation More organisms born that environment can support Organisms compete for resources Those organisms with favorable variations have more babies and the population evolves

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