1Which of the following is/are true of proteins? Check all that apply.
Select one or more:
a. Primary structure is the order of amino acids.
b. Hydrophobic amino acids tend to be on the outside of a protein.
c. Alpha helices and beta sheets are patterns of folding found in proteins.
d. Proteins are immune to pH and temperature changes.
a. Primary structure is the order of amino acids.
c. Alpha helices and beta sheets are patterns of folding found in proteins.
2Each carbon atom can bond with as many as________ other atom(s) or molecule(s).
Four
3What is the precursor to steroid hormones such as estrogen, testosterone, and cortisol?
Cholesterol
4Why are essential amino acids “essential?”
They must be eaten in the diet.
5An amino acid is to a polypeptide as:
a nucleotide is to a nucleic acid.
6A saturated fatty acid is one in which:
All of the carbons in the hydrocarbon chain are bonded to the most possible hydrogen atoms.
7What is a major role of molecules such as glucose and starch in the body?
Energy source
8What do phospholipids do?
Make up much of the cell membrane and help determine what goes in and out of the cell.
9Cellulose is nearly identical to starch; however, we cannot digest cellulose. Why?
Cellulose molecules have a different shape.
10What is the role of nucleic acids?
Store genetic information and use directions to make proteins.
11Unsaturated fats have all of the following characteristics EXCEPT:
a. they are liquid at room temperature
b. they have double bonds within the carbon chain
c. they are usually obtained from plant sources
d. they tend to dissolve in water easily
d. they tend to dissolve in water easily
12Beta-oxidation is...
The breakdown of fatty acids.
13Glucose is the only fuel that can be used in cellular respiration to generate ATP. (true or false)
False
14Why would an organism that needs to do all 3 phases of cellular respiration suffer without oxygen?
The electron transport chain stops without oxygen.
15Why do your cells go through all the steps of cellular respiration?
To make ATP.
16What do the electrons added to NAD+ do?
They go to another pathway for ATP production.
17Different steps in cellular respiration occur in different locations in the mitochondria. Which of the following does NOT properly match a step of respiration to its proper location?
A. a gradient of hydrogen ions phosphorylates ATP: Golgi membrane
B. molecule of CO2 released: matrix
C. energy transferred from NADH and FADH2 to ATP: inner mitochondrial membrane
D. two carbons manipulated through the Krebs cycle: matrix
A. a gradient of hydrogen ions phosphorylates ATP: Golgi membrane
18What role do the electrons play in the electron transport chain?
Transfer energy for proton pumps to work.
19What are the products of the preparatory reaction in cellular respiration?
NADH
acetyl CoA
carbon dioxide
20Which is NOT true about glycolysis?
a. A single glucose molecule is broken down by glycolysis to produce two pyruvate molecules.
b. A single glucose molecule produces 2 net ATP in glycolysis.
c. Two NAD+ become two NADH in glycolysis.
d. NAD+ picks up pyruvate at the end, carrying it to the Krebs cycle.
d. NAD+ picks up pyruvate at the end, carrying it to the Krebs cycle.
21Which process produces the most ATP?
electron transport chain
22What are the products of the Krebs Cycle?
CO2
energy
electron carriers
23Fermentation reactions generally occur under conditions of:
low oxygen
24What type of fermentation occurs in humans when the muscles don't get enough oxygen, such as during a sprint?
lactic acid fermentation
25When do organisms use fermentation instead of cellular respiration?
when there is not enough oxygen present
26Which of the following statements about fermentation is NOT correct?
A. Fermentation is a more efficient energy producer than aerobic respiration.
B. Fermentation utilizes the electrons generated in the glycolytic breakdown of glucose.
C. Fermentation is an anaerobic process.
D. In fermentation, the molecules that are used as final electron acceptors differ from those used when glycolysis occurs in the presence of oxygen.
A. Fermentation is a more efficient energy producer than aerobic respiration.
27How do enzymes do their job?
They bind the substrate(s) at the active site, inducing a reaction to make products.
28Why does a misspelling in the primary structure of an enzyme inhibit its function?
Enzyme shape is incorrect
Enzyme fails to bind substrate
29A competitive inhibitor:
Binds to the active site on the enzyme, blocking substrate molecules from the site.
30Enzymes:
Increase the rate at which a reaction occurs.
31What would influence the rate of an enzyme catalyzed reaction?
substrate concentration
temperature
pH
presence of inhibitors or activators
32Which of the following does the enzyme primase synthesize?
RNA primer
33 In DNA replication, when the DNA molecule separates into two strands:
it is possible to reconstruct all the information on the missing strand because one strand carries all the information needed to construct its complementary strand.
the rebuilding process begins, in which an enzyme connects the appropriate complementary base to the exposed base.
34A scientist randomly mutates the DNA of a bacterium. She then sequences the bacterium’s daughter cells, and finds that the daughters have many errors in their replicated DNA. The parent bacterium likely acquired a mutation in which enzyme?
DNA polymerase III
35If the sequence of the 5'-3' strand is AATGCTAC, then the complementary sequence has the following sequence:
3'-TTACGATG-5'
36In a DNA helix, the nitrogenous bases are _____________, the sugar molecules are _______________, and the phosphates are ___________. (inside or outside)
inside; outside; outside
37DNA is a macromolecule that stores information. Which component of DNA is the source of this information?
the base
38 The double helix model of DNA suggested by Watson and Crick was exciting to the scientific community because:
It explained how genetic material could be duplicated by means of the complementary strands.
39 All cells in the same organism have the same set of DNA. (true or false)
True
40If DNA of a particular species was analyzed and it was found that it contains 27 percent A, what would be the percentage of C?
23%
41Why are carbohydrates and proteins important in the human diet?
Carbohydrates provide energy, and proteins are essential for building and repairing tissues.
42What was the significance of the Griffith and Avery-MacLeod-McCarty experiments?
They demonstrated that DNA is the molecule responsible for heredity.
43What did the Hershey and Chase experiment using bacteriophages demonstrate?
That DNA is the genetic material, not protein.
44What did the Meselson and Stahl experiment show about DNA replication?
That DNA replicates in a semi-conservative manner, with one old and one new strand.
45What is the purpose of using PCR (polymerase chain reaction) and gel electrophoresis in a lab?
To copy DNA and separate fragments by size for analysis.
46Why is feedback inhibition important in metabolic pathways?
It allows cells to stop producing a substance when it’s no longer needed.