Molecules and Cells ReviewChapters 1-12

I. Molecules and Cells (25%)

A. Chemistry of Life (7%) 1.Water 2.Organic molecules in organisms 3.Free energy changes 4.Enzymes

B. Cells (10%)1.Prokaryotic and eukaryotic cells 2.Membranes 3.Subcellular organization 4.Cell cycle and its regulation

C. Cellular Energetics (8%) 1.Coupled reactions 2.Fermentation and cellular respiration 3.Photosynthesis

Properties of water

• Cohesion/Adhesion • High specific heat• High heat of vaporization• Lower density of ice• Solubility– Water ionizes – pH = -log[H+]• Buffers

Organic Macromolecules

• Carbs - glucose - glycosidic linkages– Energy, structure (glucose, starch, glycogen, cellulose)

• Lipids - glycerol and fatty acids - esther linkgaes, non-polar or amphipathic– Membranes, ENERGY (phospholipids, saturated/unsat)

• Nucleic Acids - nucleotides (two types - purines, pyrimidines) - phosphodiester linkages - – Info storage/transmittance, energy transmit (ATP< NAD+, FAD)

• Proteins - amino acids - peptide bonds– Defense, transport, support, motion, regulation, enzymes

• 4 levels– N-C bond, H-bonds, hydro rxns, subunits

Cell Structure

• Abiogen– First cells (pro, ana, hetero) ~ 2.5 bya– Endosym theory

• All cells have 4 things (DNA, membrane, cytoplasm, ribosome)

• Prokary– Cell walls (peptido), flagella, circular DNA, plasmids

• Eukary– Endomembrane system

• Nucleus, ER(R/S), Golgi, Vesicles (Transport, Lyso, Peroxi)– Double-membrane, DNA containing

• Mitochondria, Chloroplast– Cytoskeleton

• Microtubules, Intermed filam, Microfila• 9+2 flagella, cilia

Cell Membranes (plasma, fluid mosaic)

• Phospholipid bilayer• Cell surface markers (glycopro, glycolip)• Transmembrane Proteins

– Transporters, enzymes, receptors, ID, adhesion, attach to cytoskele• Selective Transport

– Diffuse through channels (ion-gated), facilitated– Osmosis aquaporins (hyper, hypo, iso)

• Pressure, balance (extrusion, isoreg/conform)– Endo/exo (phago, pino, receptor-mediated)– Active transport

• Na+/K+ (3 out, 2 in, maintains electrochem for nerves)– G proteins send messages (cAMP)

• Cascades• Junctions

– Tight, anchoring, communicating (gap, plasmodes)

Energy transfer

• Light - organic - ATP*• Redox– Anabolic, catabolic

• Req enzymes– Proteins*, active site, induced fit• Influenced by: temp, pH, salinity, concentration,

inhibitors (compet/alloster), activators• Cofactors (non-proteins)

• Regulated

Harvesting Energy - Step One (-synthesis)

• Photo or chemo (building = endergonic)• Chloroplast -- Outer memb, Inner mem, granum (stacks of

thylakoid), stroma filling– Light rxns - capture energy - thyla membrane, space

• Surface of thyla has photosystems (II and I)• (ETC) -- Energy received, split water, e- excited, e- transferred (loose

energy when pumping H+), energy received, e- transferred to NADP– H+ accumulate in thylakoid space, down electro to make ATP

– Light-indep - fix carbon, stroma• Energy from ATP, reducing power from NADPH• Rubisco enzyme fixes CO2 to RuBP (every 3 cycles produces 1 G3P

which can be used to build glucose, etc– When CO2 is low, O2 will bind, breaking down RuBP

» Stomata was closed to prevent water loss, limits gas exchange» Use PEP carboxylase instead» C4 in bundle sheath vs msophyll» CAM in PM vs AM

Harvesting Energy - Step Two

• Breakdown = exergonic -- ALL CELLS– Aerobic vs*. anaero– Glycolysis (anero) - cytoplasm

• 10 rxns that breakdown/rearrange glucose into pyruvate (reqs ATP, produces substrate-level ATP, produces NADH)

• Phosphofructokinase = regulating enzyme• Recycling NADH needs Final e- acceptor - oxygen, lactic acid, alcohol

– Oxidation of Pyruvate (lose e-) - Intermemb space• Pyruvate dehydrogenase = regulating enzyme, CO2 produced, NADH produced,

forms Acetyl coA (used lots)– Kreb’s/Citric Acid Cycle - matrix

• remove CO2 and store e- in NAD+ (2x), store e- in FAD, make ATP– ETC - matrix and intermembrane space

• NADH and FADH2 accum in matrix• Drop off e- at transm proteins, transfer uses energy to pump H+ into intermem

space• FADH2 2nd • Chemiosm. Potential -- H+ only pass through ATP synthase

• Sugars, proteins, fats!

Cell Cycle

• Chromosomes = coiled DNA, chromatin, histones, beads on a string, euchromatin, heterochromatin, Diploid, haploid, homologous, centromere, sister chromatids

• 5 phases = G1, S, G2, M, C (G0)– Mitosis has 4 stages (PMAT)

– P = condensation, assemble spindle (kinetochore)– M = alignment– A = pushing and pulling– T= reform nucleus

• *Cytokin= not mitosis, plants vs animals (fungi all in nucleus)– Impt signals = Cdks at checkpoints

• G1/S = external influences (growth factors, nutrition, DNA), irreversible• G2/M = correct DNA replication (mitosis promoting factor)• Metaphase/Spindle = irrerversible, prepares for anaphase

– Cancer = uncontrolled cell proliferation• Protein p53 protects DNA from damage or initiates apoptosis• Oncogenes = cancer, proto-onco prevents• Tumor suppressor