unit 3 quiz review Flashcards
Why might adding inorganic phosphate to a reaction mixture where glycolysis is rapidly proceeding help sustain the metabolic pathway?
The metabolic intermediates of glycolysis are phosphorylated
Two ATP molecules are expended in the energy investment phase of glycolysis. Why is this energy necessary to begin the process of glucose catabolism?
Glucose is a stable molecule; thus, some energy must be invested to make the molecule unstable and begin the process of catabolism
The enzyme phosphofructokinase is the major regulatory enzyme of glycolysis. It catalyzes:
The phosphorylation of fructose 6-phosphate
In lactic acid fermentation the final electron acceptor is:
pyruvate
A cell has enough available ATP to meet its needs for about 30 seconds. What is likely to happen when an athlete exhausts her ATP supply?
Catabolic processes are activated that generate more atp
When one of the eight Krebs cycle intermediates is added to the respiration medium of living cells, like yeast, what happens to the rates of ATP and carbon dioxide production?
The rates of ATP production and carbon dioxide production both increase.
What is the function of coenzyme A in the Krebs cycle?
it is the coenzyme of acetylation reactions
Where does a substrate-level phosphorylation occur in the Krebs cycle
GDP is phosphorylated to produce GTP
Which of the following statements concerning cellular metabolism is false?
Krebs cycle activity is dependent solely on availability of substrate; otherwise, it is unregulated
Which of the following statements about the following reaction is true?
Malate + NAD+ → oxaloacetate + NADH + H
Malate is moce reduced than oxaloacetate
Where is most of the water in the following reaction produced?
C6H12O6 + 6O2 → 6 CO2 + 6H2O
ETC
ATP production by ATP synthase, which requires a proton gradient across a membrane, occurs in which of the following processes?
Oxidative phosphorylation and photophosphorylation
Which of the following statements regarding photosynthesis and cellular respiration is correct
Organelles are required to carry out photosynthesis and cellular respiration in eukaryotes
true statements about chloroplasts
they are related to plastids
the have outer membranes and inner membranes
the have their own dna
they have an internal membrane system known as a thylakoids
Complete the following sentence: “The proteins of the electron transport chain active in the light-dependent reactions…
are membrane proteins present in the thylakoid
Other than proteins, thylakoid membranes must contain a large number of which of the following molecules in the reaction centres in order to harvest light energy?
electron carrier? pigments absorb energy but are not electron carriers
The absorption spectrum of a plant which shows what wavelengths of light the plant absorbs depends on
Wavelengths of light to which the plant’s pigments respond
The light-independent reactions of plants function to make organic molecules using carbon dioxide as a carbon source. What is the electron source that helps reduce carbon dioxide to sugars and other organic molecules?
NADPH
How are the light-dependent and light-independent reactions of photosynthesis related
The products of light-dependent reactions are used in light-independent reactions
the carbon fixation step of the Calvin cycle, ribulose-1,5-bisphosphate (a five-carbon compound) is carboxylated to produce
two 3-carbon compounds
Which of the following is a limiting factor of photosynthesis?
CO and light
You want to construct a molecule that will migrate easily through a cell membrane. What properties should you give your molecule?
it should be hydrophobic or uncharged or nonpolar or small in size
What is the most important factor in explaining why diffusion occurs spontaneously?
it leads to an increase in entropy
What is the most important factor in explaining why osmosis occurs spontaneously?
it leads to an increase in entropy
The term “phospholipid” can best be described by which of the following
a nonpolar lipid molecule that is made amphipathic by the addition of a phosphate
Which aspect of phospholipids is most important to the formation of bilayers?
they are amphipathic
Why do lipid bilayers form spontaneously
the process is exergonic
Which of the following is true about secondary active transport?
A gradient is set up by a pump which then provides the potential energy to move a different molecule against its concentration gradient.
Which of the following best describes sodium-potassium pumps?
They move two potassium ions and three sodium ions while consuming an ATP for each cycle
Which of the following is not a difference between passive facilitated transport and active transport?
Active transport requires a membrane protein to move molecules across the plasma membrane, while facilitated transport does not.
