You Asked for it…..

1. You Asked for it….. Biology REVIEW

2. biomolecules

3. CELLS PROKARYOTIC EUKARYOTIC 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. 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. CELL TRANSPORT

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

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)

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

9. AtpcYCLE CLICK THE ICON FOR SOUND

10. Asexual vs Sexual Reproduction Asexual Reproduction Sexual 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 mitosis Meiosis Two divisions 2n  n Half the number of chromosomes Results in 4 DIFFERENT haploid cells Forms gametes (egg and sperm) • One division • 2n  2n • (same number of chromosomes) • Results in 2 genetically identical cells

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. Protein Synthesis • 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

15. PROTEIN SYNTHESIS

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

17. READING THE CODON CHART • 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 GAGUAU CUC UAU = tyr CUC = Leu

18. Genetics • This diagram shows the cross between 2 heterozygous purple flowers • Cross is: Bb x Bb • Notice that 75% are purple and 25% white • 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

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

20. CODOMINANCE – BLOOD TYPE • 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 • 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. XY = male KARYOTYPE 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 TRANSGENIC organisms DNA FINGERPRINTING 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 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 • 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