It's MCAT Biology, Not Rocket Science

Prokaryotic: unicellular, no nuclear envelope to separate genetic material from cytosol, cell wall, no glycolipids or cholesterol in plasma membrane, flagella that are extensions of plasma membrane, plasmids, no organelles.

Eukaryotic: can be unicellular (protists)

Bacilli (rod-shaped)
Cocci (spherical)
Spirilli (spiral)
Archae- and eubacteria

Increasing unsaturation ("kinks") increases membrane fluidity and permeability.

Adding cholesterol decreases both.

In a hypotonic environment, cells swell and burst.

In a hypertonic environment, cells shrivel and shrink.

2° active transport: after 1 active transport process creates a concentration gradient, this gradient may drive other active transport processes.

Symport if the coupled component(s) moves in same direction as 1^st one; antiport if not.

They have an active site whose serine residue has an OH group that can act as a nucleophile, attacking the carbonyl C of an amino acid residue in a protein chain. They cleave proteins. They have a recognition pocket near the active site to attract certain residues on substrates for cutting on the side of the resiudue.

MAFP question: Negligible protease activity b/c covalent binding is irreversibly inhibiting.
Additional substrate can't displace MAFP.

They are generally globular catalysts (only upon folding so that the specific active site can form!) that lower the kinetic barrier but have no effect on thermodynamics.

Cooperativity: an enzyme or protein like Hb in tense (inactive) conformation becomes relaxed by substrate binding, which increases affinity for additional substrate.

Cooperativity (nH) is defined as how concerted the binding and release of O2 from hemoglobin's 4 binding sites is. It doesn't apply to myoglobin, which only has 1 binding site.

CO2 is a noncompetitive inhibitor of Hb but can dissociate from Hb when it is exhaled in the lungs. CO is a competitive, reversible inhibitor of Hb w/ greater affinity than O2.

A) Acetyl CoA, NAD+ and FAD
B) O2, NADH, FADH2

A) 2 ATP per glucose and pyruvate are produced from breakdown of glucose to which a phosphate is added.
B) NAD+ and FAD get reduced to NADH and FADH2. 2 GTP per glucose are produced.
C) NADH and FADH2 are oxidized to NAD+ and FADH2. ATP is produced.

A) cytoplasm
B) mitochondrial matrix
C) mitochondrial matrix
D) mitochondrial inner membrane

Allows for generation of products that normally wouldn't be produced spontaneously b/c a spontaneous process drives a nonspontaneous process to make it spontaneous overall. Thermodynamics, not kinetics, are affected. The delta Gs are additive, but the equilibrium constants are multiplied! Ex) ATP hydrolysis drives unfavorable rxns by either causing the protein to change shape or activating it by transferring a phosphate to it.

Complex I: The NADH dehydrogenase remains in a reduced state b/c e- build up.
Complex IV: stays oxidized b/c no e- flow.
O2 consumption (last part of chain) decreases.
Proton gradient is diminished.
ATP synthesis is compromised.

Basic (high) b/c protons are pumped across the inner membrane into the intermembrane space due to e- transport.

CO2 falls b/c 1 CO2 per pyruvate is released in the complex, which is in the matrix. No acetyl CoA can be produced from the pyruvate, so Krebs activity decreases.