Lesson Three - Amino Acid, R-Chains and the Peptide Bond

Question 1

What is a Heteropolymer?

Answer 1

A different things/ groups that join together

Question 2

What are proteins and why?

Answer 2

Heteropolymers as the amino acids which join to create the protein are different

Question 3

How many human amino acids are there?

Answer 3

20

Question 4

What type of bonds join amino acids together?

Answer 4

Peptide bonds/amide links

Question 5

What chemical groups are in the amino acid structure?

Answer 5

Carboxylic group (COOH) Amino group (NH2)

Question 6

Draw a basic amino acid structure

Answer 6

Question 7

What is the ionised form of an amino acid also known as?

Answer 7

The disociated form

Question 8

When do amino acids become ionised?

Answer 8

If the pH of solution is neutral any amino acids in solution will be ionised

Question 9

How do amino acids develop an ionised form?

Answer 9

The amino acid will either loose/gain protons to the solution which causes the compound to have a charge

Question 10

What are zwitterions?

Answer 10

Are neutral molecules with positive and negative chrages

Question 11

What is an easy way to identify if an amino acid is in the non-polar/hydorphobic group?

Answer 11

It is a hydrocarbon

Question 12

What can a zwitterion act as?

Answer 12

A base (accepting H+ ions) An acid (donating H+ ions)

Question 13

What is the charge of zwitterions dependant on?

Answer 13

The pH of the solution it is in

Question 14

What is an R-group?

Answer 14

A collective term for a polymer/a chemical chain

Question 15

What do R-groups do to amino acids?

Answer 15

Give them their unique chemical properties such as charge and solubility

Question 16

What are the 4 classifications of R groups?

Answer 16

Acidic (Negatively charged) Basic (Positively charged) Uncharged polar Non-polar

Question 17

What is the solubility of the 4 classifications of R groups?

Answer 17

Hydrophilic: Acidic (Negatively charged) Basic (Positively charged) Uncharged Polar Hydrophobic: Non-polar

Question 18

How many acidic amino acids are there?

Answer 18

2

Question 19

What chemical group do acid amino acids have?

Answer 19

Carboxyl groups (They have more than one)

Question 20

Give 2 examples of acidic amino acids

Answer 20

Aspartic Acid (Asp, D) Glutamic Acid (Glu, E)

Question 21

How many basic amino acids are there?

Answer 21

3

Question 22

What chemical group do basic amino acids have?

Answer 22

NH3+ (Once they have reacted with the neutral solutions)

Question 23

Give two examples of basic amino acids

Answer 23

Lysine (Lys, K) Arginine (Arg, R)

Question 24

How many uncharged polar amino acids are there?

Answer 24

5 and they are all hydrophilic

Question 25

What chemical group do uncharged polar amino acids have?

Answer 25

They all have different functional groups but most contain at least on -OH group

Question 26

Give two examples of uncharged polar amino acids

Answer 26

Serine (Ser, S) Asparagine (Asn, N)

Question 27

What is the meaning of hydrophilic compounds?

Answer 27

Compounds which are water loving ie. are soluble in water

Question 28

What is the meaning of hydrophobic coumpounds?

Answer 28

Compounds which are water hating i.e. they are insoluble in water

Question 29

How many amino acids are non-polar?

Answer 29

10

Question 30

Give three examples of non-polar amino acids

Answer 30

Glycine (Gly, G) Alanine (Ala, A) Cysteine (Cys, C)

Question 31

What are amino acids and what do they form when they are linked together?

Answer 31

Monomers which are linked to make a polypeptide

Question 32

What chemical reaction causes the joining of amino acids?

Answer 32

Condensation reaction (Dehydration reaction)

Question 33

Explain the process of how amino acids are joined together

Answer 33

The first amino acid looses an -OH group and the second amino acid looses a H+ group. These groups combine to create water. The two amino acids then bind creating an amide link (peptide bone)

Question 34

Draw an amide link

Answer 34

(INSERT IMAGE)

Question 35

What is the plasma membrane made up of?

Answer 35

Fluid mosaic bilayer which consists of phospholipids and proteins

Question 36

What does amphipathic mean?

Answer 36

When a compound has a hydrophilic and hydrophobic side

Question 37

Explain why the plasma membrane is amphipathic?

Answer 37

As it has a hydrophilic head group which align to the extracellular space or cytoplasm and the hydrophobic tail points inwards (similar to washing detergent)

Question 38

What is the term used to describe a protein which is within the membrane?

Answer 38

Integral

Question 39

What is the term used to describe a protein which is attached to the surface of the membrane?

Answer 39

Peripheral

Question 40

What determiines where a protein is positioned in the membrane?

Answer 40

The R groups

Question 41

Where are hydrophilic proteins positioned in the cell membrane?

Answer 41

In the peripheral part of the membrane (Outside)

Question 42

Where are hydrophobic proteins positioned in the cell membrane?

Answer 42

In the integral part of the membrane (Inside)

Question 43

What does the plasma membrane consist of?

Answer 43

Mainly fluid mosaic bilayer of phospholipids and protein

Question 44

What is amphipathic nature?

Answer 44

(of a molecule, especially a protein) having both hydrophilic and hydrophobic parts

Question 45

Where are the hydrophilic head groups aligned in the plasma membrane?

Answer 45

The extracellular space or the cytoplasm

Question 46

Where do the hydrophobic tails point in the plasma membrane?

Answer 46

They point inwards