Quizzes 1-3 Flashcards
(48 cards)
Which contain polar bonds:
NH2, CH3, O=O, OH, COOH
NH2, OH, and COOH
True or false: within cells, sodium ions are usually surrounded by a shell of oriented water molecules
True
True or false: as individual monosaccharides join to form a polysaccharide, water is released as part of the chemical reaction
True
In this type of bond/interaction, the electrons are physically shared between the interacting atoms
Covalent bonds
If a particular carbon atom is present in a stable, geometrically planar structure, it must have at least one of these bonds
Double bonds
An acidic amino acid like aspartate interacts with a basic amino acid like lysine in this manner
Ionic bond
How do enzymes act
By decreasing the activation energy
Tyrosine
Can be phosphorylated
A low dissociation constant (Kd) suggests…
…a strong binding interaction
Which has the most energy: a H bond, an ionic bond, a carbon-carbon bond, or the bond between the 2nd and 3rd phosphates of ATP?
A carbon-carbon bond
Eukaryotic cells are typically __% water by weight
70%
True or false: when salt dissolves in water, it breaks down into individual ions, each of which is surrounded by a shell of water molecules
True
True or false: in an aqueous solution, the aggregation of smaller lipid droplets into a single large lipid droplet is energetically unfavorable
False. It is favorable
True or false: when you dissolve freeze-dried protein powder in water, the proteins break down into individual amino acids
False
True or false: Hsp60 chaperonins exist only in higher vertebrates
False
True or false: humans have ~100x more protein coding genes than nematode worms or fruit flies
False
Which of the following can be observed in a standard light microscope without super-resolution?
A virus, a bacterium, a red blood cell, ATP synthase, a single protein, a carbon atom
A bacterium and a red blood cell
In a pair of western blots from 2D gels, you find that “your favorite protein” resolves as a single “dot” in the sample of untreated cells but as a pair of side-by-side “dots” (along the X axis) in the sample of cells that were treated with drug X overnight. What is the MOST likely explanation for this result?
In the untreated sample, your protein is phosphorylated. In the treated sample, your protein exists in both a phosphorylated and unphosphorylated form.
Functions of IDRs
Protein binding region with the capacity to bind to many different diverse partners
A flexible tether
In combination with others to form a diffusion barrier
Signaling via covalent modifications
What techniques are most commonly used to determine whether two proteins function in the same molecular complex?
Co-immunolocalization and co-immunoprecipitation
True or false: a mutation in the first 3’ splice site such that the first splice is made to the second 3’ splice site might lead to a smaller than normal mRNA being produced
True
True or false: a mutation in the first 5’ splice site such that the first splicing reaction starts with the second 5’ splice site might lead to a smaller than normal mRNA being produced
False
What changes could repress transcription?
Methylation of histone tails
Replacement of histones near the promoter with specialized histones that are normally restricted to centromeric regions
What would increase the fraction of AB dimers?
Increase the concentration of B, esp if B is “rate limiting”
Introduction of a scaffolding protein that can bind to both A and B
