CMB Lecture 4

Question 1

Chaperonins

Answer 1

Facilitate the correct folding of the proteins and protects the polypeptide from degradation, refold or mark for destruction if misfolded.

Question 2

Functions of proteins (x8)

Answer 2

Enzymes. Defensive. Storage. Transport. Hormones. Receptors. Contractile/motor proteins. Structural proteins.

Question 3

Most __ are proteins and biological catalysts.

Answer 3

Enzymes

Question 4

Antibodies have roles in our ___ and are produced by ___ cells.

Answer 4

immune system, immune cells.

Question 5

Immune cells recognize potential threats when ___.

Answer 5

Antibodies bind to viruses or bacteria.

Question 6

__ can be used for storage.

Answer 6

Storage proteins can be used for storage.

Question 7

Transport molecules do what?

Answer 7

Facilitate the movement of hydrophobic molecules across membrane.

Question 8

Hemoglobin protein

Answer 8

Transports o2 to other tissues throughout the body.

Question 9

Hormones

Answer 9

Some lipids to proteins.

Question 10

Receptors:

Answer 10

Detect chemical signals.

Question 11

Contractile/motor proteins

Answer 11

Facilitates contractions, motor proteins can walk along microtubules, dragging vesicle.

Question 12

Cytoskeleton is made up of ___ that ___(x3)

Answer 12

proteins, that can move vesicles around the cell, maintain cell shape, and anchor organelles.

Question 13

Every amino acid has an _ group and a _ group.

Answer 13

amine, carboxyl

Question 14

The part of the amino acid that differs is __

Answer 14

The R group, or side chain.

Question 15

The carbon that links the amino group, side chain, and carboxyl group is __

Answer 15

The alpha carbon.

Question 16

Peptide bonds are formed by __

Answer 16

Dehydration reactions.

Question 17

Primary structure:

Answer 17

Sequence of amino acids , the linear arrangement of the amino acids.

Question 18

The sequence of the __ __ will determine how the polypeptide folds and its final 3d structure.

Answer 18

Side chain.

Question 19

The primary structure or amino acid sequence is specified by __

Answer 19

Nucleotides in DNA.

Question 20

Once mRNA has been processed, it exits through the ___

Answer 20

nuclear pores.

Question 21

Secondary structure is where the polypeptide will__

Answer 21

undergo repeated coiling and folding.

Question 22

Alpha _ and beta __

Answer 22

helix, pleated sheet.

Question 23

Secondary structures are stabilized by __

Answer 23

hydrogen bonds, which form between repeating regions of the backbone of the polypeptide.

Question 24

The hydrogen bonds form between the __ and the __, stabilizing the structure.

Answer 24

H+ and O-.

Question 25

T/F: R groups can have charge, interfere with the formation for these hydrogen bonds.

Answer 25

True.

Question 26

Coils are held together by H-bonding every __

Answer 26

4th amino acid, often found in regions of transmembrane that cross the lipid bilayer.

Question 27

The a-helix are joined together by __

Answer 27

Non-coiling regions.

Question 28

B-pleated sheets make up many of the _ ___

Answer 28

globular proteins.

Question 29

___ describes the overall 3D structure/conformation of the polypeptide chain.

Answer 29

Tertiary structure

Question 30

Most polypeptides will be folding in a ___ environment.

Answer 30

Hydrophillic.

Question 31

What happens to amino acids with nonpolar environments?

Answer 31

They will be pushed to the center of the polypeptide, creating hydrophobic interactions with one another, and Van Der Waals interactions.

Question 32

If two opposingly electrically charged side cahins come close together they will form ___.

Answer 32

ionic bonds.

Question 33

What is a disulfide bridge?

Answer 33

A strong S-S bond that occurs when there are two cysteine amino acids. As the polypeptide folds and comes into contact, they will form a disulfide bridge, a strong covalent bond.

Question 34

Quaternary structure.

Answer 34

Final 3D structure, bonded with other fully folded polypetides in order to fully carry out its function.

Question 35

Some Q structures can be just one polypeptide structure. (T/F?)

Answer 35

True.

Question 36

The polypeptides in a Quaternary structure can be the ___

Answer 36

same or different.

Question 37

_____ proteins cause many diseases.

Answer 37

Misfolded. Cell must get the amino acids in the correct sequence with correct folding.

Question 38

How chaperonins work (x3)

Answer 38

An unfolded pp enters the cylinder from one end. 2. Cap attaches, causing the cylinder to change its shape that creates a hydrophillic environment. 3. Cap comes off, and the properly folded protein is folded.

Question 39

Chaperonins consists of:

Answer 39

A cap protein, and a hollow cylinder protein.

Question 40

Polypeptides fold ___ into proteins.

Answer 40

Spontaneously

Question 41

Denaturation is:

Answer 41

Destruction of the 2nd, 3rd, 4th structure.

Breakage of H bonds, hydrophillic and hydrophobic interactions and S=S bonds

Question 42

Causes of denaturation:

Answer 42

Heat, pH, reducing agents, organic solvents, detergents

Question 43

What effect does hydrolysis of a polypeptide have?

Answer 43

This breaks down the primary structure of a polypeptide

Question 44

Denaturation: Reducing agents do what?

Answer 44

Reduce disulfide bonds to sulfhydryl groups

Question 45

Denaturation: pH effect

Answer 45

Changes ionization of R groups

Question 46

Denaturation: organic solvents

Answer 46

disturb hydrophobic and hydrophillic interactions

Question 47

Denaturation: detergents

Answer 47

Disturb hydrophobic interaction

Question 48

Renaturation:

Answer 48

When the denaturing agent is removed, some proteins are able to refold back into the correct 3D shape. All that is required to fold is in the sequence of the amino acid.