Exam 2 Flashcards
What is the framework of the membrane structure?
Phospholipid bilayer
What kind of molecules do phospholipids contain?
Amphipathic molecules
What components do the membrane structure contain?
Proteins and carbohydrates
What are the three types of proteins bound to membranes?
Transmembrane proteins, lipid anchored proteins, and peripheral membrane proteins
What do the transmembrane proteins do?
have one or more regions physically embedded in the phospholipid bilayer
What do lipid-anchored proteins do?
lipid-molecule is COVALENTLY attached to an amino acid side chain within the protein; lipid tails are inserted into the membrane
what do peripheral membrane proteins do?
NON COVALENTLY bound either to integral membrane proteins that project out from the membrane, or to polar head groups of phospholipids
What percentage of genes encode transmembrane proteins?
20-30%
How are computer programs used for transmembrane proteins?
predict the number of transmembrane proteins in an organism based on DNA sequence data of an organisms genome
What is cystic fibrosis?
A lung disease caused by a problem with transmembrane proteins in membranes
What is fluidity?
Individual molecules remain in close association but can readily move within a membrane
Molecules capable of enzymatic activity include
A. RNA and DNA
B. Proteins only
C. RNA and proteins
D. DNA and proteins
E. RNA only
C. RNA and proteins
In a biochemical pathway, the product released by the first enzyme becomes the substrate for the second enzyme.
True or False
True
Inhibiting one step in a biochemical pathway will not have any affect on the rates of the other reactions in the pathway.
True or False
False
Where is sucrase found in the human body?
A) on the gastric surface
B) in the pancreas
C) in the liver
D) on the microvilli of the small intestine
D. On the microvilli of the small intestine
Sucrose uses ____ to cleave sucrose into two monosaccharides
A. Oxygen
B. Carbon dioxide
C. Water
D. Glucose
E. Fructose
C. Water
What happens to sucrase when it binds to sucrose?
A. Sucrase goes through a conformational change
B. Sucrase becomes denatured
C. Sucrase is cleaved in half
D. Sucrase releases energy to the sucrose
A. Sucrase goes through a conformational change
How often can a Sucrase molecule be used to hydrolyze sucrose?
A. Once
B. Twice
C. Many times
D. Never
C. Many times
Most enzymes are
A. Carbohydrates
B. Polysaccharides
C. Lipids
D. Steroids
E. Proteins
E. Proteins
Which of the following binds most tightly to the active site of an enzyme?
A. None of these choices are correct
B. Substrate
C. Product
D. Water
E. Any other enzyme
B. Substrate
An enzyme catalyzes a chemical reaction in the cell, but can only be used once.
True or False
False
An enzyme may catalyze a reaction by stressing or destabilizing the bonds of the substrates. This critical point in the enzymatic reaction is known as the
A) activation energy
B) change in free energy
C) energy state
D) transition state
E) enzyme-substrate complex
D. Transition state
Cells obtain energy by _________ food molecules such as glucose.
A) reducing
B) phosphorylating
C) anabolizing
D) redoxing
E) oxidizing
E. Oxidizing
What happens when the coenzyme NAD+NAD+ gains an H atom?
A. It also gains an electron causing it to be oxidized
B. It loses energy
C. It also gains an electron causing it to be reduced
D. It also gain a proton causing it to be reduced
E. It also gains a proton causing it to be oxidized
C. It also gains an electron causing it to be reduced
A hydrogen atom consists of
A. Electrons only
B. protons only
C. A proton and an electron
D. A proton and several electrons
E. A variable number of protons and electrons
C. A proton and an electron
Which of the following is the correct equation for aerobic cellular respiration?
A) glucose + 6 O2O2 + 6 H2OH2O → 6 CO2CO2 + energy intermediates + heat
B) glucose + 6 O2O2 + 6 CO2CO2 → 6 H2OH2O + energy intermediates + heat
C) glucose + 6 CO2CO2 → 6 O2O2 + 6 H2OH2O + energy intermediates + heat
D) glucose + 6 O2O2 + heat → 6 CO2CO2 + 6 H2OH2O + energy intermediates
E) glucose + 6 O2O2 → 6 CO2CO2 + 6 H2OH2O + energy intermediates + heat
E) glucose + 6 O2O2 → 6 CO2CO2 + 6 H2OH2O + energy intermediates + heat
If glycolysis was blocked in yeast, which of the following would decrease in concentration?
A. Oxygen
B. Ethanol
C. Pyruvate
D. NAD+
E. Carbon dioxide
C. Pyruvate
Fatty acids and some amino acids are converted directly into ____ for ATP production
A. Pyruvate
B. NADH
C. Glucose
D. FADH2
E. Acetyl CoA
E. Acetyl CoA
Before entering the critic acids cycle (Krebs cycle) Pyruvate is converted to
A. Glucose
B. H2OH20 and CO2CO2
C. Acetic acid
D. Acetyl-CoA
E. Oxaaloacetate
D. Acetyl-CoA
The citric acid cycle (Krebs cycle) occurs in the mitochondrion.
True or False
True
Electrons are brought to the electron transport system by the oxidation of
A. NADH
B. FADH2
C. ATP
D. Oxygen
E. NADH and FADH2
E. NADH and FADH2
The movement of protons through ATP synthase occurs from the
A. Matrix to the intermembrane space
B. Matrix to the cytoplasm
C. Intermembrane space to the matrix
D. Intermembrane space to the cytoplasm
C. Intermembrane space to the matrix
Creation of protein gradient by the electron transport chain represents
A. Heat
B. Potential energy
C. Kinetic energy
B. Potential energy
Synthesis of ATP via a proton gradient is called
A. Glycolysis
B. Krebs cycle
C. Chemiosmosis
C. Chemiosmosis
The electron transport chain in bacteria is located
A. In the cytoplasm
B. In the mitochondria
C. In the cell wall
D. In the cell membrane
D. In the cell membrane
During aerobic respiration, the last carrier protein transfers a pair of electrons to
A. Water
B. NADH
C. Oxygen
D. Coenzyme Q
E. A proton ( H+)
C. Oxygen
The function of the enzyme ATP synthase is to
A. Accept a proton from inside the cell membrane as it accepts electrons
B. Utilize the energy of the proton motive force to convert ADP to ATP
C. Produce reduced coenzymes like NADH
D. Transfer hydrogen to the electron transport chain
E. Shuttle electrons from NADH to the terminal electron acceptor
B. Utilize the energy of the proton motive force to convert ADP to ATP
How do electrons enter the electron transport chain?
A. By the oxidation of NADH
B. By the reduction of NADH
C. By the reduction of oxygen
D. By the oxidation of water
A. By the oxidation of NADH
Which of the following are examples of potential energy?
A. Electrons in chemical bonds, proton gradient, ATP
B. Electrons moving through electron transport chains, proton gradient
C. Protons moving through ATPase, ATP
D. Electrons moving through the electron transport chain, and protons moving through ATPase
A. Electrons in chemical bonds, proton gradient, ATP
When NADH donates electrons to the electron transport chain NADH is
A. Being reduced
B. A endergonic reaction
C. Being oxidized
C. Being oxidized
Once ATP donates its phosphate to a coupled reaction it becomes ADP. The ADP
A) Can be recharged in an endergonic reaction to form ATP.
B) Is a waste product that must be broken down.
C) Can be recharged in an exergonic reaction to form ATP.
D) Can be recharged in an equilibrium reaction to form ATP.
E) Can be recharged in an oxidation reaction to form ATP.
A. Can be recharged in an endergonic reaction to form ATP
