Biology Exam 2
15. _____ is the product of the Calvin Cycle that is used to form glucose phosphate, amino acids, or fatty acids.
. a. Glyceraldehyde-3- phosphate (G3P)
Consider the biochemical pathway: A - E1 -> B - E2 -> C that is irreversible. If Enzyme 2 is inactive, which of the following compounds will accumulate
B only
To what does the term stroma refer?
The fluid-filled space of the chloroplast
6. ATP is considered to be
a. A molecule that carries a great deal of chemical energy in a chemical bond
To what does the term grana refer?
a. A stack of thylakoid of the chloroplast
8. Endergonic reactions:
a. Can only occur if there is an input of energy
8. Which of the following is a common photosynthetic pigment found in plants?
a. Chlorophyll a b. Carotenoids c. Chlorophyll b
14. What structure is required for an eukaryotic organism to be classified as an autotroph?
a. Chloroplast
9. Which best describes the 1st law of thermodynamics?
a. Energy is not created nor destroyed, but it can change from one energy form to another
16. A product of photosynthesis _______ is the chief source of energy for most organism.
a. Glucose
12. Enzymes speed up chemicals reactions by
a. Lowering the energy of activation required
What are the end products of photosynthesis?
a. Oxygen and carbohydrates
11. Oxygen production in photosynthesis involves which of the following?
a. Photosystem II b. Splitting of water c.Light reactions
If plants were no longer able to perform the light reactions and they could only utilize the calvin cycle, which of the following would be true?
a. Plants would not produce oxygen b.G3P would be produced in much smaller quantities
1. While we are sitting down to lunch, we are consuming _____ energy, which will then be converted into _____ energy as we work until dinner time.
a. Potential; Kinetic
4. Lactose is milk sugar, and as infants, humans produce substantial amounts of the lactase enzyme to digest it. However, as we age, we soon lose some or even all of our lactase. In such cases, undigested lactose passes to the lower intestine where bacteria break it down into lactic acid and CO2, causing painful gas and bloating. This problem could be avoided by
a. Taking lactase enzyme tablets or avoiding all diary products
2. During the conversion of glucose into a free form of energy only some of the energy is converted into usable ATP. What happens to the rest of the energy?
a. The energy is converted to heat
13. Protons (H+) accumulate in the thylakoid space during electron transport between photosystems II and I. Which of the following describes what will happen to these protons next?
a. The protons will move from the thylakoid space to the stroma through an ATP synthase complex that generates ATP
5. You are interrupted while eating some yogurt and you store the remaining yogurt in the refrigerator. A day later you return and find the surface of the yogurt is no longer smooth but has broken into several liquified areas. You correctly guess that enzymes from your saliva, via the spoon, have continued digesting the yogurt in your absence. If you left the yogurt on the counter for another 24 hours, what would happen?
a. The reaction will continue since the enzymes have plenty of substrate. Additionally, it would speed up since the enzymes are exposed to warmer temperatures.
19. Which of the following statement(s) about biochemical pathways is(are) TRUE?
a. They are very well organized and structured and they convert an initial substrate via a series of steps into an end product
Why are plants green?
a. They reflect green wavelengths of light and absorb other colors of the visible light spectrum
17. Fossil fuels are full of energy stored from photosynthesis millions of years ago.
a. True
7. Coupling occurs when the energy released by an exergonic reaction is
a. Used to drive an endergonic reaction
10. The sum of the chemical reaction in a cell constitute
metabolism
18. Consider the biochemical pathway: A - E1 -> B - E2 -> C Enzyme 1 can utilize
only A as a substrate
11. Enzymes have no effects on the energy levels of the reactants or products of reactions only the energy of activiation
true
13. Enzymes are catalysts that speed up chemicals reactions
true
16. In a biochemical pathway, the product of the first reaction becomes the substrate in the second reaction
true
3. Enzyme inhibition is the process that turns off an enzyme in a metabolic pathway. One way this can happen is for the end product of the pathway to act as an inhibitor.
true
14. The energy of activation is best describes as
a. the energy threshold that must be reached before a reaction can proceed and products may be formed.
15. All biochemical pathways have the same number of enzymatic reactions.\
false
18. The light-dependent reactions of photosynthesis occur in the stroma of the chloroplast.
false
