What role does the citric acid cycle play in amino acid metabolism?
a. breakdown of glucogenic amino acids feeds metabolites into the citric acid cycle
b. amino acid synthesis often relies on intermediates of the citric acid cycle
c. breakdown of ketogenic amino acids feeds metabolites into the citric acid cycle
a, b, & c
a & b
In: Biology
In: Biology
Amino acids occasionally are used as buffers. A buffer is a solution that resists changes in pH when acid or base are added. The pH range over which a buffer is effective is called the buffering range, usually defined as pKa + 1 to pKa -1.
a. Indicate the buffering range (or ranges) of Gly, His, Asp and Lys .
b. Choose an amino acid to buffer at pH = 4, pH =6, pH =9, and pH =12.
c. Would you expect a protein containing 100 amino acids to be as good a buffer as its constituent free amino acids at equivalent molar amino acid concentrations? Explain.
In: Chemistry
1.The amino acid serine is classified as a(n) _________________________________________________ amino acid.
2.A type of chromatography that fractionates proteins based on differences in their size is ____________________________________ chromatography.
3.
In Anfinsen's experiments on the structure and function of RNase, he found that non-covalent bonds were key in determining the _________________________ structure of the enzyme.
4.
A type of reversible enzyme inhibitor that binds to the active site of an enzyme and prevents the substrate from binding the active site is is called a ___________________________________________________ inhibitor.
5.Chymotrypsin activity includes the formation of an acyl-enzyme intermediate, formed as a result of bond formed between a carbonyl carbon in the polypeptide undergoing cleavage and a hydroxyl oxygen on the side chain of the amino acid _____in the enzyme's active site. Prior to this binding, this amino acid donates a proton from its hydroxyl group to the amino acid____ also found in the enzyme's active site.
In: Biology
The main function of tRNA is to *
Identify amino acids and transport/ carries them to ribosomes
Induce the ribosome translocation
Inhibit protein synthesis
Catalyze the peptide bonds between two amino acids
In: Biology
Which of the following statements about active exclusion of sodium are true?
| a. |
It is dependent on a proton gradient and ATP |
|
| b. |
It requires antiporters that exchange H+ for Na+ |
|
| c. |
It prevents accumulation of sodium in plant cells |
|
| d. |
It allows for greater uptake of sodium into plant cells |
|
| e. |
All of the above statements are true EXCEPT D |
Double fertilization refers to:
| a. |
Cross-pollination by two distinct mechanisms (e.g. wind and bees) |
|
| b. |
The formation of male (n) and female (n) gametes |
|
| c. |
The development of a fruit in an angiosperm |
|
| d. |
The process of embryogenesis and seed maturation |
|
| e. |
The formation of a zygote (2n) and primary endosperm nucleus (3n) |
One important difference between the anatomy of roots and the anatomy of leaves is that _____.
| a. |
Leaves are covered in a waxy cuticle and stomata, which is absent from roots |
|
| b. |
Only roots have ground tissue |
|
| c. |
Only leaves have epidermal tissue |
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| d. |
Root cells have cell walls and leaf cells do not |
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| e. |
Roots contain vascular tissue, whereas leaves do not |
Which of the following statements regarding ATP is true?
| a. |
It has high potential energy because it is reduced. |
|
| b. |
It provides energy coupling between exergonic and endergonic reactions. |
|
| c. |
It is a highly stable storage form of energy in cells. |
|
| d. |
It is not able to regulate enzyme activity. |
|
| e. |
All of the above. |
You consume a large meal rich in carbohydrates and protein. Cellular concentrations of acetyl-CoA and NADH increase significantly. What will happen as a result?
| a. |
The rate of the citric acid cycle will increase |
|
| b. |
Excess acetyl-CoA will be used to make glucose for storage as glycogen |
|
| c. |
Excess acetyl-CoA will be used to synthesize fatty acids for storage in adipose (fat) tissue |
|
| d. |
Excess acetyl-CoA will be used to synthesize new amino acids and proteins |
|
| e. |
All of the above |
You expose a plant that contains chlorophyll a, chlorophyll b, and carotenoids to different wavelengths of light, then measure the level of resonance-energy transfer. Which of the following results would you expect?
| a. |
Oxygen production is highest upon exposure to yellow light |
|
| b. |
Oxygen production is highest upon exposure to blue light |
|
| c. |
Oxygen production is highest upon exposure to white light |
|
| d. |
Oxygen production is highest upon exposure to green light |
|
| e. |
Oxygen production is highest upon exposure to far red light |
High levels of ATP will impact cellular respiration by:
| a. |
Decreasing rates of pyruvate processing to acetyl-CoA |
|
| b. |
Increasing rates of glycolysis and the citric acid cycle by allosteric activation of enzymes |
|
| c. |
Decreasing rates of glycolysis and the citric acid cycle by competitive inhibition of enzymes |
|
| d. |
Decreasing rates of glycolysis and the citric acid cycle by allosteric inhibition of enzymes |
|
| e. |
ATP levels do not impact the rates of cellular respiration pathways |
When consumed, fatty acids provide more calories per gram than carbohydrates because:
| a. |
Fatty acids have a greater number of C-O bonds, where electrons are NOT shared equally |
|
| b. |
Fatty acids are the most important form of chemical energy for all organisms |
|
| c. |
Fatty acids have a greater number of C-O bonds, where electrons are shared more equally |
|
| d. |
Fatty acids have a greater number of C-C and C-H bonds, where electrons are shared more equally |
|
| e. |
Fatty acids are smaller molecules |
You isolate an enzyme from the human stomach to test its activity. In order to measure optimal enzyme function, which of the following laboratory conditions should you use in the experimental reactions?
| a. |
Solutions with a pH ~2 |
|
| b. |
Reaction temperature close to normal body temperature (98.6°F) |
|
| c. |
Include substrates for which the enzyme has high affinity |
|
| d. |
Include high concentrations of substrate |
|
| e. |
All of the above |
In glycolysis, glucose-6-phosphate (G-6-P) is converted to fructose-6-phosphate (F-6-P). Which of the following statements about this reaction is true?
| a. |
G-6-P is a hexose, whereas F-6-P is a pentose |
|
| b. |
ATP is spent to form F-6-P |
|
| c. |
ATP is generated in the formation of F-6-P |
|
| d. |
A 5-point monosaccharide ring structure is formed, allowing for the addition of a second phosphate group in the subsequent step |
|
| e. |
All of the above are correct |
You are conducting a plant growth experiment in a research laboratory. Prior to setting up your experiment, you notice that ~25% of the seed coats appear damaged. You plant them anyway, but notice that ~25% of your plants fail to germinate. All of the plants have been watered regularly, and have received adequate light. What is the most likely cause of the lack of germination?
| a. |
The hypocotyls were damaged |
|
| b. |
The cotyledons were damaged |
|
| c. |
The radicles were damaged |
|
| d. |
A mutation that interfered with asexual reproduction |
|
| e. |
All of the above likely occurred |
In humans, fermentation results in the formation of ________, whereas fermentation in yeast results in the formation of _________. In humans, this pathway occurs when ________ is absent.
| a. |
Lactate; glucose; ATP |
|
| b. |
Lactate; ethanol; oxygen |
|
| c. |
Citrate; glucose; ATP |
|
| d. |
Pyruvate; ethanol; NAD+ |
|
| e. |
Ethanol; lactate; oxygen |
Which of the following statements regarding the Calvin Cycle are correct?
| a. |
The rate will be increased by a loss-of-function mutation in rubisco |
|
| b. |
The rate will be increased by having NADP+ available only in its oxidized form (rather than its reduced form) |
|
| c. |
It is an endergonic process |
|
| d. |
It occurs during the night time in most plants |
|
| e. |
All of the above are correct |
All of the following statements regarding structural polysaccharides are true, EXCEPT:
| a. |
They form parallel strands that are joined together by peptide or hydrogen bonds |
|
| b. |
Structural polysaccharides include cellulose, chitin, and peptidoglycan |
|
| c. |
They are comprised of β-glucose molecules |
|
| d. |
They can be found in the cell walls of plants and external skeletons of insects |
|
| e. |
They can easily be broken down by phosphorylase |
In: Biology
why is proline more hydrophilic than all of the other hydrophobic amino acids? ( need to consider the electronegativity of nitrogen and carbon and then carefully look at proline's structure in relation to other hydrophobic amino acids
In: Chemistry
What is an amino acid? How many amino acids are
there?
In: Biology
1.Type of fiber that slows gastric emptying and lowers blood glucose.
Polysassacharide
Soluble
HDL
Insoluble
2.What is meant by Amino Acid Sequence?
Number of side chains in the protein
Folding arrangement of the peptide chain
Order of amino acids in the peptide chain
Order of the essential amino acids in the protein
In: Biology
In: Chemistry