Membrane proteins:

I) are sometimes covalently attached to lipid moieties.

II) are sometimes covalently attached to carbohydrate moieties.

III) are composed of the same 20 amino acids found in soluble proteins.

IV) move across the membrane unless they are anchored

Which of the following combination is correct?

#Question id: 10531

#Unit 2. Cellular Organization

Flippases catalyze translocation of the aminophospholipids:

#Question id: 10532

#Unit 2. Cellular Organization

A  closed, self-sealing solvent-filled vesicles that are bounded by only a single bilayer, known as:

#Question id: 10533

#Unit 2. Cellular Organization

Following statements are regarding to the fluidity of a bilayer.

A. A lipid bilayer cools below a characteristic transition temperature, it undergoes a sort of phase change in which it becomes a liquid; that is, it loses its fluidity.

B. Above the transition temperature, the highly mobile lipids are in a state known as a liquid crystal.

C. The bilayer is thicker in the gel state than in the liquid crystal state due to the stiffening of the hydrocarbon tails at lower temperatures.

D. The transition temperature of a bilayer decreases with the chain length and the degree of saturation of its component fatty acid residues for the same reasons that the melting points of fatty acids increase with these quantities.

Which of the following combination is correct?

#Question id: 10534

#Unit 2. Cellular Organization

This experiment (shown in figure ) was performed at 37degree C. If the experiment were carried out at 10 degree C, what effect would you expect on the rate of diffusion? Why?

#Question id: 10535

#Unit 6. System Physiology – Plant

The insect ingests plant tissue containing the fatty acids, an enzyme in the gut conjugates the plant-derived fatty acid to an insect-derived amino acid to form an elicitor, When plants recognize elicitors from insect saliva induces some typical responses such as

a) Increasing Ca²⁺ levels in the cytosol and then activate an array of target proteins, such as calmodulin and other Ca²⁺-dependent protein kinases

b) In Arabidopsis, a calmodulin-binding transcriptional regulator called IQD1 was identified as an important mediator of defense responses against insect herbivory

c) overexpression of IQD1 in Arabidopsis activate the herbivore activity

d) IQD1 binds calmodulin, a major Ca2+-binding protein, in a Ca2+-dependent manner and subsequently inhibits the gene involved in glucosinolate biosynthesis

Which of the following combination from above statements is correct?

#Question id: 10536

#Unit 6. System Physiology – Plant

Hormonal interactions contribute to plant–insect herbivore interactions such as— ethylene, salicylic acid, and jasmonic acid. In particular, ethylene appears to play an important role in this context, what will be the effect of ethylene when is applied alone and when is applied with other amino acids?

a) ethylene applied together with JA it seems to reduces defense responses

b) Ethylene appears to applied alone to plants, ethylene has little effect on defense-related gene activation

c) when ethylene applied together with JA it seems to enhance JA responses or defense responses are significantly increased

d) Ethylene appears to applied alone to plants, ethylene has more effect on defense-related gene activation

Which of the following combination is correct about ethylene effects?