BIOMOLECULES Carbohydrate Protein Building Block Uses Examples Test Simple sugars Ready source of energy Glucose Glycogen Cellulose Starch • Enzymes (ase) Hemoglobin Antibodies Protein hormones (insulin) • Reacts with Biuret Solution Fats, oils • Leaves oily spot on brown paper bag DNA, RNA • DNA stains (methylene blue) Amino acids • Transport • • • Lipid Fatty Acids • • Nucleic Acid Nucleotide Speed up reactions Immunity Cell communication Back up energy source In membrane Store and transmit genetic info • STARCH turns purple in iodine SUGARS react with Benedict’s Solution CELLS E U K A RYOTIC P ROK A RYOTIC • •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 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 lipid and protein • It controls what goes in and out of a cell. • Associated with HOMEOSTASIS CELL TRANSPORT Diffusion Osmosis Active Transport Movement from high to low concentration Movement of water from high to low WATER concentration across a membrane Movement from LOW concentration to HIGH concentration No energy required No energy required USES ATP PHOTOSYNTHESIS AND RESPIRATION CONVERTS SUNLIGHT TO CHEMICAL ENERGY CONVERTS ENERGY IN FO O D (G LU C O S E ) TO AT P Cellular Respiration •Takes place in mitochondrion •Releases the energy stored in glucose •AKA aerobic respiration (NEEDS oxygen) AEROBIC VS ANAEROBIC RESPIRATION A E RO B IC R E S PIR AT IO N A N A E RO B IC R E S PIR AT IO N •Does not use oxygen •Makes only 2 ATP • Requires oxygen • Makes A LOT of ATP • Produces carbon dioxide and water • Also called fermentation • Happens in mitochondrion • Happens in cytoplasm (cytosol) • Small amount of ATP • YEASTS make ethyl alcohol • BACTERIA and MUSCLE CELLS (w/o O2) make LACTIC ACID ATP CYCLE CLICK THE ICON FOR SOUND 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 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) 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 RNA PROTEIN •DNA is in nucleus •GENES (made of DNA) hold code for protein •mRNA is made in nucleus •TRANSCRIPTION •Remember base pairing rules •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 CAN YOU IDENTIFY THE PARTS? 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. DNA mRNA Nucleus Cytoplasm Ribosome Codon Anticodon tRNA Amino acid Protein (polypeptide) 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 GAG UAU CUC UAU = tyr CUC = Leu 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 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 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 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) XY = male 3 21’s = Down Syndrome • • • • • 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) GENETIC TECHNOLOGY DNA FINGERPRINTING TRANSGENIC ORGANISMS •Gene cloning •Use gel electrophoresis to compare DNA fragments •Uses bacteria to make human proteins like insulin •IF DNA matches, it’s from the same individual •Organisms that have 2 different kinds of DNA Evidence points to suspect 2 EVOLUTION – CHANGE OVER TIME EVIDENCE N AT U R A L S E LE C T IO N •Fossil evidence •Credited to Charles Darwin • 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 • 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