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
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?
a. easily translocated
b. chemically non-reactive
c. easily digested by animals
d. osmotically inactive
e. synthesized during photosynthesis
The useful properties are:
1. (a), (b) and (e)
2. (a) and (e)
3. (b) and (c)
4. (b) and (d)
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
Most of the functions of a cell membrane can be attributed to its:
1. Phospholipids
2. Cholesterol
3. Proteins
4. Carbohydrates
Consider the following two statements regarding enzyme action:
I: | Co-factors play a crucial role in the catalytic activity of the enzyme. |
II: | Catalytic activity is reduced when the co-factor is removed from the enzyme. |
Of the above statements:
1. Both I and II are correct and II explains I
2. Both I and II are correct but II does not explain I
3. I is correct but II is incorrect
4. I is incorrect but II is correct
Conjugated proteins containing carbohydrates as prosthetic group are known as
1. Chromoproteins
2. Glycoproteins
3. Lipoproteins
4. Nucleoproteins
Which is an essential amino acid?
1. Serine
2. Aspartic acid
3. Glycine
4. Phenylalanine
The transfer RNA molecule in 3D appears
1. L-shaped
2. E-shaped
3. V-shaped
4. S-shaped
Length of one turn of the helix in a B-form DNA is approximately
1. 3.4 nm
2. 2 nm
3. 0.34 nm
4. 20 nm
ATP is a
1. nucleotide
2. nucleosome
3. nucleoside
4. purine