REVIEW IS IMPORTANT….. BIOLOGY CA#2 REVIEW

BIOMOLECULES Building BlockUsesExamplesTest (optional) CarbohydrateSimple sugars Ready source of energy Glucose Glycogen (animals) Cellulose Starch (plants) STARCH turns purple in iodine SUGARS react with Benedict’s Solution ProteinAmino 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 AcidNucleotide Store and transmit genetic info DNA, RNA DNA stains (methylene blue)

CARBOHYDRATES Monomer- monosaccharide Function- energy source and structure Tests: glucose-Benedicts starch- Iodine Polymer- Polysaccharide fructose Ex. Cellulose, glycogen (animals), starch (plants)

LIPIDS Made of fatty acids and glycerol Function- energy storage and insulation Tests: brown paper test Non polar and insoluble in water. Examples: fats and steroids Lipid vs. water

NUCLEIC ACIDS Monomer- nucleotide Function- carry genetic information Ex. DNA and RNA

CELLS PROKARYOTIC 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. 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.

CELL MEMBRANE The plasma membrane surrounds EVERY cell. It is made of phospholipid bilayer and protein It controls what goes in and out of a cell. Maintains HOMEOSTASIS

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

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

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)

ASEXUAL VS SEXUAL REPRODUCTION ASEXUAL REPRODUCTION Creates identical copies (clones) Only involves MITOSIS ONE parent involved Common in bacteria and unicellular protists SEXUAL REPRODUCTION Adds genetic variation Involves meiosis and fertilization TWO parents involved Diploid and haploid cells

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

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

BASE PAIR RULE In DNA, Adenine always pairs with Thymine, and Guanine always pairs with Cytosine

DNA REPLICATION Process of DNA copying itself happens in S-Phase of the cell cycle. 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)

CENTRAL DOGMA DNA  RNA  protein  trait

DNA / RNA DNA Double stranded “Double Helix” Four base pairs: ATGC Sugar is Deoxyribose Found in nucleus RNA Single stranded Four base pairs: AUCG Sugar is Ribose

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

PROTEIN SYNTHESIS DNA DNA is in nucleus 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

1.DNA 2.mRNA 3.Nucleus 4.Cytoplasm 5.Ribosome 6.Codon 7.Anticodon 8.tRNA 9.Amino acid 10.Protein (polypeptide) CAN YOU IDENTIFY THE PARTS?

TRANSLATION Connects amino acids in the correct order to make a protein Occurs in the cytoplasm within the ribosomes A- amino acid B- tRNA C- anticodon D- codon E- mRNA F- Ribosome G-polypeptide

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

HOW TO USE THE CODON CHART

WHAT ARE MUTATIONS? Changes in the nucleotide sequence of DNA produces different amino acid sequence hence a protein not needed by the cell. May occur in somatic cells (aren’t passed to offspring) May occur in gametes (eggs & sperm) and be passed to offspring

MUTATIONS Change in DNA code May cause a change in protein produced NOT always harmful Sickle Cell Mutation

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 GENETICS

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) SEX LINKAGE 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 CODOMINANCE – BLOOD TYPE Agglutinogen = protein

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)

KARYOTYPE 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) A chart showing arrangement of chromosomes XY = male 3 21’s = Down Syndrome

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

EVOLUTION – CHANGE OVER TIME EVIDENCE 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 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

Charles Darwin – proposed that organisms (species or populations) change over time Occurs by Natural Selection – “survival of the fittest” Lines of evidence 1) fossils (geologic time) 2) Homologous Structures –same basic structure formed from same embryonic tissue 3) Analogous Structures – same basic functions due to same environmental pressures 4) Vestigial Structures – structures that have lost function ex) appendix 5) Embryology – embryos of various species appear identical 6) Biochemistry – DNA and protein amino acid sequence comparisons Adaptive radiation – an ancestral species radiates or diverges into many species. Ex) Galapagos Finches Origin Ideas Urey and Miller simulated Earth’s early environment and created organic compounds like amino acid Endosymbiotic theory – eukaryotic cells formed when prokaryotic cells began to live together permanently H omologous Vestigial