Protein section 2

MrSujg
Quiz by MrSujg, updated more than 1 year ago
MrSujg
Created by MrSujg about 4 years ago
68
2

Description

1st year Biochemistry and molecular biology Quiz on Protein section 2, created by MrSujg on 11/22/2015.
Tags

Resource summary

Question 1

Question
Amino acids are grouped according to their [blank_start]physico-chemical[blank_end] properties and this is reflected in the genetic code
Answer
  • physico-chemical
  • binding
  • structural
  • biological

Question 2

Question
A single base change in the [blank_start]third[blank_end] position of the codon will often produce the same amino acid and in the [blank_start]second[blank_end] position often one with very similar physico-chemical properties.
Answer
  • third
  • first
  • second
  • second
  • third
  • first

Question 3

Question
The second base of the codon specifies whether an amino acid is...
Answer
  • polar or hydrophobic
  • basic or acidic
  • primary or secondary
  • aromatic or non-aromatic

Question 4

Question
Why are conservative substitutions good
Answer
  • because of them mutation events in the DNA sequence do not lead to a change in the function
  • they induce molecular evolution
  • they repair DNA

Question 5

Question
How many levels of protein structure are there
Answer
  • 3
  • 2
  • 1
  • 4
  • 5

Question 6

Question
Match the level of the structure with the image
Answer
  • Secondary
  • Primary
  • Tertiary
  • Quaternary

Question 7

Question
The amino acid sequence of the protein, dictated by the genetic code. This sequence contains all the information needed to specify:
Answer
  • Primary structure
  • Secondary structure
  • Tertiary structure
  • Quaternary structure

Question 8

Question
Regular repeating patterns of hydrogen-bonded backbone conformations such as alpha-helices and beta-sheets.
Answer
  • Primary structure
  • Secondary structure
  • Tertiary structure
  • Quaternary structure

Question 9

Question
The primary structure also dictates how these the structural elements pack together to form the overall shape of the protein in the form of folds. This is called the...
Answer
  • Tertiary structure
  • Quaternary structure
  • Folding structure

Question 10

Question
This represents the overall relative arrangement of two or more individual tertiary folded polypeptides.
Answer
  • Primary structure
  • Secondary structure
  • Tertiary structure
  • Quaternary structure

Question 11

Question
Reactivities of the elements involved in the primary structure
Answer
  • The overall polypeptide chain
  • The peptide bond
  • The amino acid R groups of the primary structure
  • The size of the amino acid sequence

Question 12

Question
Resonance is the result of [blank_start]delocalisation[blank_end] of [blank_start]electrons[blank_end] over several [blank_start]atoms.[blank_end]
Answer
  • delocalisation
  • deprotonation
  • protonation
  • electrons
  • side chains
  • hydrogen atoms
  • atoms
  • molecules

Question 13

Question
Resonance decreases the polarity of the peptide bond and each has a dipole moment.
Answer
  • True
  • False

Question 14

Question
As we mentioned previously there is rotation allowed around [blank_start]N-Cα[blank_end] and [blank_start]Cα-C[blank_end] by angles phi and psi Thus we have a polymer with rotatable covalent bonds which alternate with rigid planar ones This [blank_start]restricts[blank_end] the number of [blank_start]conformations[blank_end] the polypeptide can adopt.
Answer
  • N-Cα
  • N-Cb
  • Cα-C
  • Cb-C
  • restricts
  • increases
  • conformations
  • bonds

Question 15

Question
Apart from the properties of the peptide bond what other chemical reactivities does the polypeptide exhibit?
Answer
  • The reactivity of the carbonyl oxygen and amide nitrogen of the peptide bond
  • The various reactivities of the R groups attached to the α-carbon of the amino acids in the primary structure.
  • The London dispersion interactions between the amino acids
  • Hydrophobic effect

Question 16

Question
[blank_start]Hydrophobic[blank_end] side chains engage in van der Waals interactions. They have a tendency to [blank_start]avoid[blank_end] contact with water and pack against each other. This is the basis for the [blank_start]hydrophobic[blank_end] effect. Tendencies: [blank_start]Alanine[blank_end] and [blank_start]leucine[blank_end]- helix favouring residues, proline -helix breaking residue
Answer
  • Hydrophobic
  • Hydrophilic
  • avoid
  • go into
  • hydrophobic
  • hydrophilic
  • Alanine
  • Methionine
  • Serine
  • leucine
  • Aspargine
  • Histidine

Question 17

Question
[blank_start]Hydrophilic[blank_end] side chains are able to make [blank_start]hydrogen[blank_end] bonds with each other, with the peptide bond, with polar organic molecules and with water. Also because some are [blank_start]charged[blank_end] and exhibit [blank_start]pKa’s[blank_end] they can change their charge depending on the [blank_start]pH[blank_end] or the microenvironment.
Answer
  • Hydrophilic
  • Hydrophobic
  • hydrogen
  • covalent
  • charged
  • neutral
  • pH
  • pKa
  • pKa’s
  • pH

Question 18

Question
[blank_start]Amphipathic[blank_end] side chains have both polar and non-polar character and are ideal at interfaces and may be involved in both [blank_start]H-bonding[blank_end] and [blank_start]van der Waals interactions.[blank_end]
Answer
  • Amphipathic
  • Acidic
  • Basic
  • H-bonding
  • Covalent bonding
  • van der Waals interactions.
  • hydrophobic interactions

Question 19

Question
Hydrogen bonds are formed when a hydrogen atom has a significant partial negative charge by virtue of being bound to a more electronegative atom such as oxygen or nitrogen and is attracted to a near neighbour (less than 0.35nm) that has significant partial positive charge.
Answer
  • True
  • False

Question 20

Question
The atom to which the hydrogen is attached is called the H-bond [blank_start]donor[blank_end]
Answer
  • donor
  • acceptor

Question 21

Question
The charge state of the donor and acceptor changes the strength of the H-bond.
Answer
  • True
  • False

Question 22

Question
To the right are some examples of H-bonding in proteins, the most important of which in the context of primary structure and its influence on the secondary structure of proteins is that between the amide [blank_start]donor[blank_end] and the carbonyl [blank_start]acceptor[blank_end] of the main chain peptide bond. The other shown are more important in tertiary structure.
Answer
  • donor
  • acceptor
  • acceptor
  • donor

Question 23

Question
ALTHOUGH PROTEINS ARE LINEAR POLYMERS THE STRUCTURES OF MOST OF THEM ARE NOT THE RANDOM COILS SEEN IN SYNTHETIC NON-NATURAL POLYMERS.
Answer
  • True
  • False

Question 24

Question
Most proteins are observed to be [blank_start]globular[blank_end] and have a [blank_start]tightly packed[blank_end] hydrophobic core which consists primarily of hydrophobic amino acids. One very striking feature of the folded polypeptide chain is that the chain of amino acids takes up conformations in which the torsion angles phi and psi of the backbone chain repeat in regular patterns.
Answer
  • globular
  • linear
  • tightly packed
  • loose

Question 25

Question
Types of secondary structure
Answer
  • Helices
  • Beta sheets
  • Beta turns
  • Globulin

Question 26

Question
The most common of these is alpha helix
Answer
  • Helices
  • Beta-sheets
  • Beta-turns

Question 27

Question
Sometimes known as pleated sheets. These sheets can exist as parallel or anti-parallel.
Answer
  • Beta sheets
  • Beta turns
  • Helices

Question 28

Question
here the chain is forced to turn sharply in a reverse direction, this small secondary structure element allows for the compact folding of proteins.
Answer
  • Helices
  • Beta sheets
  • Beta turns

Question 29

Question
The network of regular [blank_start]secondary[blank_end] structures contributes very significantly to the [blank_start]stability[blank_end] of the overall folded protein providing extensive networks of [blank_start]hydrogen[blank_end] bonds in which many consecutive residues are involved. All of the [blank_start]hydrogen[blank_end] bonding capability in the secondary structure of a protein is contributed from the amide nitrogen and carbonyl oxygen of the main chain peptide bond as [blank_start]donor[blank_end] and [blank_start]acceptor[blank_end] respectively. This hydrogen bonding provides much of the stabilising [blank_start]enthalpy[blank_end] which allows the polar backbone amide and carbonyl groups to exist in the very [blank_start]hydrophobic[blank_end] environment in the interior of a folded protein.
Answer
  • secondary
  • primary
  • stability
  • conformation
  • size
  • hydrogen
  • covalent
  • hydrogen
  • covalent
  • donor
  • acceptor
  • acceptor
  • donor
  • enthalpy
  • entropy
  • hydrophobic
  • hydrophylic

Question 30

Question
The carbonyl oxygen atom (n) of each residue accepts an H bond from the amide nitrogen four residues further along (n+5)
Answer
  • True
  • False

Question 31

Question
All of the polar amide groups of this helix are hydrogen bonded to each other except the [blank_start]first[blank_end] amide hydrogen and the [blank_start]last[blank_end] carbonyl oxygen.
Answer
  • first
  • second
  • third
  • last
  • fifth
  • fourth

Question 32

Question
The helix forms a [blank_start]cylindrical[blank_end] structure with the walls formed by the H bonded backbone with the side chains pointing [blank_start]outwards[blank_end].
Answer
  • cylindrical
  • tetrahedral
  • spherical
  • outwards
  • inwards

Question 33

Question
What is amphipathic, in what type of secondary structure can it be seen
Answer
  • hydrophobic nature on one side of the helix and hydrophilic on the other; helices
  • hydrophobic nature on one side of the helix and hydrophilic on the other; beta turns
  • acidic nature on one side of the helix and basic on the other; beta sheets
  • acidic nature on one side of the helix and basic hydrophilic on the other; coils

Question 34

Question
Steric factors favour the left handed helix.
Answer
  • True
  • False

Question 35

Question
No theoretical limit to the length of helices, very long ones up to hundreds of Angstroms have been observed in keratin (Hair protein).
Answer
  • True
  • False

Question 36

Question
formed between main chain amide hydrogen and carbonyl oxygen come from backbone groups distant from each other in the primary sequence.
Answer
  • Helices
  • Beta sheet
  • Beta turns

Question 37

Question
The strands can run in the same direction and be parallel beta sheets or in opposite directions and be anti-parallel beta sheets. It is also possible to get mixed sheets with both parallel and anti-parallel strands together. What direction is more stable?
Answer
  • anti-parallel
  • parallel

Question 38

Question
indicate the directionality of the sequence
Answer
  • Antiparallel
  • Parallel
  • Parallel
  • Antiparallel

Question 39

Question
Nearly all polar amide groups are [blank_start]hydrogen[blank_end] bonded to one another in a sheet structure The N-H and C=O groups on the outer sides of the sheets, the edge strands are not H bonded to other strand members. These residues can H bond to [blank_start]water[blank_end], or may pack against polar side chains in perhaps a nearby [blank_start]helix[blank_end]. [blank_start]Parallel[blank_end] sheets are always buried. Anti-parallel sheets are however frequently exposed to solvent and are probably [blank_start]more[blank_end] stable structures than parallel sheets.
Answer
  • hydrogen
  • covalently
  • water
  • substrate
  • helix
  • beta sheet
  • Parallel
  • Anti-parallel
  • more
  • less

Question 40

Question
parallel sheets are always separated by another structural element usually [blank_start]helices[blank_end]. beta sheet polypeptide chains are nearly fully extended (unlike helices) with distances between residues being up to [blank_start]3.3[blank_end]Angstroms. beta strands always have a pronounced [blank_start]right[blank_end] handed twist due to steric factors arising from the [blank_start]L-amino[blank_end] acid configuration. [blank_start]Valine[blank_end] and [blank_start]isoleucine[blank_end] are residues more commonly found in sheets. Beta strands can be [blank_start]amphipathic[blank_end] due to the alternating consecutive side chain configuration. These strands are found on the [blank_start]surface[blank_end] of proteins.
Answer
  • helices
  • beta turns
  • 3.3
  • 3.4
  • 3.5
  • right
  • left
  • L-amino
  • D-amino
  • Valine
  • Threonine
  • Cysteine
  • isoleucine
  • Alanine
  • Glycie
  • amphipathic
  • amphoteric
  • surface
  • inside

Question 41

Question
BETA SHEETS CANNOT FORM BARREL STRUCTURES
Answer
  • True
  • False

Question 42

Question
What kind of protein is it?
Answer
  • Retinol binding protein
  • Retinol inhibiting protein
  • Cadherin binding protein
  • Cadherin inhibiting protein

Question 43

Question
Here we see retinol binding protein with a distinct [blank_start]beta barrel[blank_end] structure. A large [blank_start]anti-parallel[blank_end] beta [blank_start]sheet[blank_end] curves all the way round with the last strand [blank_start]hydrogen[blank_end] bonded to the first thus forming a closed cylinder. The interior of the cylinder is lined with [blank_start]hydrophobic[blank_end] residues and can accommodate retinol which is [blank_start]non-polar[blank_end].
Answer
  • beta barrel
  • alpha helix
  • anti-parallel
  • parallel
  • sheet
  • turns
  • hydrogen
  • nitrogen
  • hydrophobic
  • hydrophylic
  • non-polar
  • polar

Question 44

Question
The simplest secondary structural element is the beta turn and usually involves just [blank_start]four[blank_end] residues. It is very important in allowing compact folding of proteins and is often found connecting the strands of [blank_start]anti-parallel[blank_end] beta sheets. The beat turn comprises a hydrogen bond from the carbonyl oxygen of one residue (n) to the amide N-H of residue [blank_start]n+3[blank_end]. This reverses the direction of the chain. Beta turn are most commonly found on the [blank_start]surface[blank_end] of proteins in contact with the aqueous environment. The tight geometry of the turn means that some amino acids such as [blank_start]glycine[blank_end] are found more commonly in turns than other bulkier groups.
Answer
  • four
  • five
  • anti-parallel
  • parallel
  • n+3
  • n+4
  • surface
  • interior
  • glycine
  • phenylalanine
  • glutamine

Question 45

Question
What limits the number and positioning of secondary structural elements
Answer
  • size of R group
  • steric constraints
  • nature of R group
  • Directionality
  • The amount of peptide bonds
Show full summary Hide full summary

Similar

Carbohydrates
kevinlinkovoor
Chapter 7 - The Blue Print of Life, from DNA to Protein
Dorothy B
DNA Basics
Sarah Juliette B
Immune System
dsandoval
DNA questions not from the lectures
MrSujg
Protein section 1
MrSujg
Viruses
marthas2705
Protein section 5
MrSujg
Protein section 3
MrSujg
HIV and the immune system
Beth Moore
Biology- Genes, Chromosomes and DNA
Laura Perry