Biology Ch. 1 Flashcards
Reactions that form and break macromolecules
Form: dehydration; produces H2O.
Break: hydrolysis.
Properties of Water
Excellent solvent
High heat capacity
More dense as liquid
Cohesion
Adhesion
Vitamin Types and What They Do
Water Soluble: Vit B (coenzymes/metabolic precursors); Vit C (collagen synthesis).
Fat Soluble: A (vision, epithelium); D (Ca absorption); E (Antioxidant); K (blood clotting).
3 Disaccharides to Know
Sucrose = glucose and fructose
Lactose = glucose and galactose
Maltose = glucose and glucose
Carbohydrates with alpha bonds and beta bonds
Alpha: starch and glycogen
Beta: cellulose and chitin
Triglycerides
Phospholipids
Steroids
Porphyrins
T: glycerol + 3 FAs
P: 2 FAs + phosphate group attached to glycerol
S: three 6 membered rings and one 5 membered ring
P: 4 pyrrole rings with a metal center atom.
How Cell Membranes respond to Temp Differences
In Cold: cholesterol and unsaturated FA added to increase fluidity.
In Hot: cholesterol and saturated FA added.
Purines vs. Pyrimidines
Purines: 2 rings, A and G
Pyrimidines: 1 ring, T, C, U
Nucleosides vs. Nucleotides
NS: sugar + nitrogenous base
NT: sugar, nitrogenous base, phosphate group
Things that can pass CM
Small, uncharged, hydrophobic molecules
Can’t: large, polar, charged
(glucose, ions)
Nucleus and Nucleolus
Nucleus: contains DNA and coordinates activities such as protein synthesis and reproduction.
Nucleolus: ribosome/rRNA sunthesis.
Rough ER
Continuous with outer nuclear membrane.
Covered in ribosomes.
Protein synthesis
Lumen allows post-translational modifications.
Smooth ER
Synthesis of lipids and steroid hormones.
Break down drugs and toxins.
Golgi Apparatus
Sorts, modifies, and transports proteins.
Makes lysosomes.
Lysosomes
Made by Golgi
Contain digestive enzymes with low pH.
Apoptosis, autophagy, breakdown of nutrients, bacteria, debris.
Peroxisomes
Common in liver and kidney
Breakdown FA and AA
Generates H2O2 to oxidize substrates.
Vacuoles
Transport and move materials.
Food: transports food and fuses with lysosomes
Central: (plants) stores water, exerts turgor.
Contractile: pump water outside of cells to prevent bursting.
Microtubules
Intermediate Filaments
Microfilaments
MT: tubulin, support/motility, spindle. Also cilia, flagella, centrioles.
IF: maintain cell shape, keratin.
MF: two actin strands, motility, cleavage furrow.
Plastids
Variety of organelles serving various metabolic activities such as chloroplasts for PS.
Peripheral Proteins
Not imbedded
Attached by H bonds and ES interactions.
Usually Hydrophilic.
Use salt or pH change to remove.
Integral
Embedded in membrane.
Known as transmembrane if it spans the entire membrane.
Hydrophobic
Use detergents to remove.
Channel vs Carrier Proteins
Channel: water, ions, aquaporins
Carrier: binds to specific molecule to allow passage.
Passive Transport + 2 Types
No energy needed; down concentration gradient.
Simple Diffusion: down conc gradient.
Facilitated Diffusion: assistance from transport proteins.
Active Transport + 2 Types
Energy required, against concentration gradient.
Primary: uses ATP directly.
Secondary: establish electrochemical gradient used to move a substance against CG.
Phagocytosis
Pinocytosis
Phagocytosis: engulfing by extending pseudopods and packaging into vacuoles.
Pinocytosis: plasma invaginates around dissolved material (liquid).
Collagen
Bones, muscles, skin, tendons.
Triple helix
Gly as every 3rd AA
Kinesin and Dynein
Motor proteins that walk on MTs.
K: center to periphery
D: periphery to center.
Exergonic vs. Endergonic
Ex: spontaneous, -G, releases energy.
End: nonspontaneous, +G, absorbs energy.
Substrate vs. Active Site
S: reactants an enzyme acts on.
AS: location on the enzyme where substrate binds.
Km
Concentration of substrate at 1/2 Vmax.
Inversely proportional to binding affinity of enzyme/substrate.
Vmax
maximum rate of the reaction.
Increase in substrate or enzyme increases Vmax.
Competitive Inhibitor
Inhibitor binds to active site.
Raises Km, no effect on Vmax.
Non-Competitive Inhibitor
Inhibitor binds to a site other than the active site.
Decreases Vmax, no effect on Km.
Locations of Glycolysis, Citric Acid Cycle, and Electron Transport Chain
G: cytosol
CAC: mitochondrial matrix
ETC: inner membrane of mitochondria
Net products of Glycolysis
2 Pyruvate
2 ATP
2 NADH
2 H2O
2 Important Enzymes in Glycolysis
Hexokinase: uses 1 ATP to phosphorylate glucose to glucose-6-phosphate. Irreversible and prevents glucose from leaving the cell.
Phosphofructokinase: irreversibly adds a second phosphate to glucose committing it to glycolysis.
(high ATP conc can inhibit this step).
Citric Acid Cycle Overview
Pyruvate is converted to Acetyl-CoA by PDC.
Acetyl-CoA goes through the cycle and regenerates oxaloacetate.
Produces CO2, ATP/GTP, FADH2, and NADH.
ETC Overview
NADH (C1) and FADH2 (C2) pass their electrons off and are oxidized.
Electrons move down the chain and pump H+ ions into the intermembrane space.
C4 passes electrons to O2 and forms water.
ATP Synthase uses flow of H+ ions to synthesize ATP via Oxidative phosphorylation.
Alcohol Fermentation
Plants, fungi, yeast.
Pyruvate converted to acetaldehyde and CO2.
Then Acetaldehyde is converted to ethanol by oxidizing NADH to NAD+.
Acetaldehyde is used as final electron acceptor.
Lactic Acid Fermentation
Human muscle cells and microorganisms.
Pyruvate + NADH –> lactate and NAD+.
Lactate can be converted back to glucose by liver (Cori Cycle).
Overview of Light Reactions of Photosynthesis
Occurs in Thylakoid Membrane
Photosystem II: electrons are energized by photons.
Electrons are passed along ETC that pumps H+ from stroma into thylakoid lumen.
These protons then power ATP synthase.
Photosystem I:
Noncyclic- electrons passed from PSII to PSI, where they are excited again by photons. They travel down another ETC to form NADPH.
Cyclic- occurs in stroma lemellae. electrons are recycled to first ETC to make more ATP.
3 Products: ATP, NADPH, O2.
Dark Reactions/Calvin Cycle
Fix CO2 into Glucose, occurs in stroma.
C4 and CAM Photosynthesis
C4: avoids photorespiration by separating light and dark reactions. Calvin Cycle moved to deeper tissues to avoid O2.
CAM: fixes CO2 at night to minimize photorespiration and water loss.
Prophase and Prometaphase
Prophase: chromatin condenses, nucleolus disappears, mitotic spindle forms, centrioles move to poles.
Prometaphase: nucleus disassembles, chromosomes condense and spindle begins to attach at kinetochore.
Metaphase
Chromosomes line up at metaphase plate.
Spindle attached at all kinetochores (checkpoint).
*karyotyping is done here.
Anaphase
Microtubules shorten and pull chromosomes to poles.
Sister chromatids now considered individual chromosomes.
Telophase and Cytokinesis
T: Nucleoli reappear, nuclear envelopes form. Chromosomes decondense and spindle disappears.
C: animal cells form cleavage furrow, plant cells form cell plate.
Meiosis I Overview
P1: homologous chromosomes pair up and form tetrads (synapsis).
Crossing over occurs (chiasmata is site where they cross over).
M1, A1, and T1 are very similar to mitosis.
Produces two haploid daughter cells that are genetically different.
Cell Cycle Checkpoints
G1: adequate nutrients and cell size.
G2: proper duplication of chromosomes/DNA.
M: sister chromatids are attached to spindles.
