Most abundant organic compound on earth is
1. Cellulose
2. Protein
3. Lipids
4. Steroids
Assuming they all had the same number of carbon atoms, which of the following has the most C-H bonds?
1. an unsaturated fat
2. a polyunsaturated fat
3. a polysaccharide
4. a saturated fat
An alpha helix is a:
1. primary structure of a protein
2. secondary structure of a protein
3. tertiary structure of a protein
4. quaternary structure of a protein
Why is cellulose so difficult for most animals to digest?
1. they don’t have the proper enzyme to break the bonds between subunits
2. cellulose is made up of chitin, which is indigestible
3. the bonds holding cellulose subunits together are extremely strong, stronger than in any other macromolecule
4. there are many hydrogen bonds holding the subunits together
Catalytic efficiency of two different enzymes is compared by their :
1. Product
2. Molecular size
3. Km value
4. pH optimum value
Which statement regarding enzyme inhibition is correct?
1. Competitive inhibition occurs when a substrate competes with enzyme for binding to inhibitor protein
2. Competitive inhibition occurs when a substrate and the inhibitor compete for active site on the enzyme
3. Non-competitive inhibition of an enzyme can be overcome by adding a large amount of substrate
4. Non-competitive inhibitors often bind to the enzyme irreversibly
Cell membrane carbohydrates participate in
1. transporting substances between two protein layers
2. cell-to-cell recognition
3. attaching the membrane to cytoskeleton
4. cell adhesions
Carbohydrates are commonly found as starch in plant storage organs. Which of the following five properties of starch (a-e) make it useful as a storage material?
(i). easily translocated
(ii). chemically non-reactive
(iii). easily digested by animals
(iv). osmotically inactive
(v). synthesized during photosynthesis
The useful properties are:
1. | (i), (ii) and (v) | 2. | (i) and (v) |
3. | (ii) and (iii) | 4. | (ii) and (iv) |
A molecule of ATP is structurally most similar to :
1. RNA nucleotide
2. DNA nucleotide
3. amino acid
4. fatty acid
In feedback inhibition, a metabolic pathway is switched off by:
1. a rise in temperature
2. lack of a substrate
3. accumulation of the end product
4. competitive inhibition