Chapter 4- Protein Structure and Function

Question 1

Give some examples of what proteins do for the cell

Answer 1

Proteins…
- Act as enzymes to catalyze reactions
- Form channels and pumps (Sodium Potassium Pump)
- Carry signals

Question 2

_________ dictates _________

Answer 2

Structure, Function

Question 3

The numerous functions of proteins result from what?

Answer 3

The huge amount of shapes that proteins can be

Question 4

Give examples of proteins

Answer 4

• Enzymes
• Structural Proteins
• Transport Proteins
• Motor Proteins
• Storage Proteins
• Signal Proteins

Question 5

What determines a proteins primary structure?

Answer 5

The amino acid sequence ( 20 different amino acids, numerous ways to combine them )

Question 6

What is the sequence of molecules that makes up the backbone?

Answer 6

NItrogen Carbon Carbon

Question 7

What are the groups of amino acids?

Answer 7

Non-polar, Negatively charged, positively charged, Uncharged Polar

Question 8

Electrostatic Attractions

Answer 8

positives and negatives coming together

Question 9

Hydrogen Bond

Answer 9

Form between polar parts of molecule

Question 10

Van Der Waals Attraction

Answer 10

Anytime two molecules get close together there is a minor attractive force

Question 11

Hydrophobic Forces

Answer 11

Hydrophobic molecules forced together in an aqueous environment to minimize effect on hydrogen bonded network

Question 12

How do proteins choose what shape to fold into

Answer 12

They fold into the shape that requires the least amount of energy (AKA Free Energy (G))

Question 13

Misfolded proteins cause what disorders?
Give Examples

Answer 13

Neurodegenerative disorders
Alzheimer’s, Huntington’s, Scrapie, BSEm CJD

Question 14

Why are misfolded proteins so dangerous?

Answer 14

They continue to produce copies and create more misfolded proteins (Almost acts like cancer)

Question 15

What do chaperone Proteins Do?

Answer 15

Hold the proteins in their correct shape as they’re forming

Question 16

How many amino acids long can a protein be?

Answer 16

30 - 10,000 amino acids long

Question 16

How many amino acids long can a protein be?

Answer 16

30 - 10,000 amino acids long

Question 17

What are the two common Secondary Structures that proteins form?

Answer 17

Alpha Helix and Beta Sheets

Question 18

Where are the side chains in Alpha Helix’s?

Answer 18

Out to the side of the twisty chain

Question 19

What is the tertiary structure?

Answer 19

The protein folding back on itself AKA the globular structure

Question 20

How to determine if a protein is a transmembrane protein?

Answer 20

If it has 7 hydrophobic amino acids in a row

Question 21

What occurs when a charged molecule needs to go through a cell membrane?

Answer 21

Two helices will wrap around each other to minimize exposure of hydrophobic amino acid side chain to aqueous environment

Question 22

Where are the side chains in beta sheets

Answer 22

Either above or below

Question 23

Parellel Beta Sheets

Answer 23

Polypeptide chains that run in the same orientation

Question 24

Antiparallel Beta Sheets

Answer 24

Polypeptides that run opposite directions

Question 25

Is a folding proteins energetically favorable or unfavorable?

Answer 25

It is energetically favorable because it releases heat and increases the entropy of the universe