Enzymes
The minimum energy required to start a reaction is called this.
Activation energy
This model describes the membrane as a dynamic bilayer with proteins embedded throughout.
Fluid Mosaic Model
The sum of all chemical reactions in a cell is called this.
Metabolism
Transcription occurs in this organelle.
Nucleus
The cytoskeletal component made of actin monomers is also called this.
Microfilaments
Enzymes lower activation energy but do NOT change this value of a reaction.
Increasing the saturation of fatty acid tails has this effect on membrane fluidity.
Decreases fluidity
A reaction with a positive ΔG is described as this.
Endergonic (or nonspontaneous)
Proteins destined for secretion are translated on ribosomes attached to this organelle.
Rough ER
The motor protein that moves along actin filaments is called this.
Myosin
Competitive inhibitors differ from noncompetitive inhibitors because they bind to this location.
The active site
These molecules can cross the membrane without assistance: small hydrophobic, large polar, or charged ions?
Small hydrophobic molecules
Hydrolysis reactions are typically classified as this type of pathway and have this sign of ΔG.
Catabolic; negative ΔG
Proteins move through the endomembrane system in this order.
ER → cis Golgi → trans Golgi → target destination
Microtubules are considered dynamic because they can rapidly do this.
Polymerize and depolymerize
A reaction has a negative ΔG but proceeds very slowly in a cell. What is the most likely reason?
A) The reaction is nonspontaneous
B) The activation energy is high
C) The cell is at equilibrium
D) The products have more free energy than reactants
B) The activation energy is high
A red blood cell is placed in a solution and begins to swell until it lyses. The external solution is most likely:
A) Isotonic
B) Hypertonic
C) Hypotonic
D) Saturated
C) Hypotonic
A cell couples ATP hydrolysis to a reaction that builds a macromolecule. This allows the overall reaction to:
A) Become nonspontaneous
B) Reach equilibrium
C) Have a negative ΔG
D) Stop requiring enzymes
C) Have a negative ΔG
A cell that secretes large amounts of digestive enzymes would likely have an abundance of which organelle?
A) Smooth ER
B) Rough ER
C) Peroxisomes
D) Lysosomes
B) Rough ER
Vesicles move from the ER to the Golgi along which structure?
A) Actin filaments
B) Intermediate filaments
C) Microtubules
D) Tight junctions
C) Microtubules
An enzyme stops functioning after a significant increase in temperature. The most likely explanation is:
A) ATP was depleted
B) The enzyme reached equilibrium
C) The protein lost its structure and active site shape
D) The reaction became endergonic
C) The protein lost its structure and active site shape
A membrane protein cluster needs to stay grouped together for signaling. The cell inserts more cholesterol into that region. What structure is being formed and why?
A lipid raft; cholesterol decreases fluidity to keep proteins clustered together
A pathway in a living cell consists of multiple steps. Why must each step individually have a negative ΔG?
Because each step must be capable of occurring spontaneously for the pathway to proceed
A mutation prevents vesicles from fusing with the trans Golgi. Which process would be directly disrupted?
Protein modification, sorting, and delivery to final destinations (including secretion and lysosome formation)
A liver cell contains many peroxisomes and smooth ER. What does this suggest about its function?
It performs significant detoxification and fatty acid processing