Module 2 Section 2 - Proteins

Question 1

What are proteins

Answer 1

Polymers

Question 2

What are amino acids

Answer 2

Monomers

Question 3

A dipeptide is …..

Answer 3

Formed when TWO amino acids join together

Question 4

A Polypeptide is…..

Answer 4

Formed when MORE THAN TWO amino acids are joined together

Question 5

All amino acids have….

Answer 5

The same general structure. A carboxyl group and amino group

Question 6

What is the difference between amino acids

Answer 6

The variable group they contain

Question 7

What elements doall amino acids contain

Answer 7

Carbon
Oxygen
Hydrogen
Nitrogen

Question 8

What do some amino acids contain

Answer 8

Sulfur (alongside C,H,O,N)

Question 9

What are amino acids linked by

Answer 9

Peptide bonds

Question 10

Amino acids and peptide bonds form to make

Answer 10

Dipeptides and polypeptides

Question 11

What is released during the reaction when amino acids are joined together

Answer 11

A molecule of water - condensation reaction

Question 12

The reverse reaction of when peptide bonds between amino acids breaks does what

Answer 12

Adds a molecule of water - hydrolysis reaction

Question 13

What are the four structural levels of protein

Answer 13

Primary
Secondary
Tertiary
Quaternary

Question 14

What is the primary structure of a protein

Answer 14

The sequence of the amino acids in the polypeptide chains

Question 15

What is the secondary structure

Answer 15

hydrogen bonds form between amino acids in the chain. This automatically coils into an alpha helix or fold into a beta pleated sheet

Question 16

What is tertiary structure

Answer 16

The coiled or folded chain of amino acids is often coiled and folded further. For proteins made from a single polypeptide chain the tertiary formed their final 3D structure

Question 17

What is quaternary structure

Answer 17

Some proteins are made from several polypeptide chains held together by bonds. For proteins made from more than one polypeptide chain, the quaternary is the protein final 3D structure

Question 18

What is the primary structure held together by

Answer 18

Peptide bonds between the amino acids

Question 19

Secondary structures are held together by…..

Answer 19

Hydrogen bonds

Question 20

Tertiary bonds are held together by

Answer 20

Ionic bonds
Disulphide bonds
Hydrophobic or hydrophilic interactions
Hydrogen bonds

Question 21

In tertiary structure ionic bonds are used to hold it together, what does this mean

Answer 21

These are attractions between negatively charged R-groups and positively charged R-groups on different parts of the molecule

Question 22

In tertiary structure disulphide bonds are used to hold it together, what does this mean

Answer 22

Whenever two molecules of the amino acid cysteine come close together, the sulfur atoms in one cysteine, bonds to the sulfur in the other cysteine forming a disulphide bond

Question 23

In tertiary structure a hydrophobic and hydrophilic interactions holds the structure together. What does this mean

Answer 23

When hydrophobic r groups are close together in the protein, they tend to clump together. This means that hydrophilic r-groups are more likely to be pushed to the outside, which affects how the protein folds up into final structure.

Question 24

In tertiary structure, hydrogen bonds are used to hold up the structure, what does this mean

Answer 24

Weak bonds form between slightly positively charged hydrogen atoms in some r groups and slightly negative charged atoms in other r groups on the polypeptide chain.

Question 25

A quarternary structure is held together by

Answer 25

tends to be determined by the tertiary structure of the individual polypeptide chains being bonded together. can be influenced by all the bonds mentioned e.g. ionic, disulphide, hydrophobic and hydrophilic interactions and hydrogen bonds

Question 26

In a globular protein what tends to be pushed on the outside of the molecule

Answer 26

The hydrophilic r-groups

Question 27

What causes the globular protein to push the hydrophilic r-group on the amino acids to the outside of the molecule

Answer 27

The hydrophobic and hydrophilic interactions in the tertiary structure

Question 28

are globular protein soluble

Answer 28

yes meaning they are easily transported in fluids

Question 29

examples of globular proteins are

Answer 29

haemoglobin
insulin
amylase

Question 30

what are the properties of a fibrous protein

Answer 30

-insoluble
-strong
-fairly unreactive

Question 31

what are the example of fibrous proteins that we need to know

Answer 31

collagen
keratin
elastin

Question 32

where is collagen found

Answer 32

animal connective tissues (bone, skin, muscle etc.)

Question 33

what can bind to the protein to increase rigidity

Answer 33

minerals

Question 34

where is keratin found

Answer 34

in many external structures of animals, such as skin, hair, nails etc.

Question 35

keratin can either be

Answer 35

-flexible (as it is in skin)
-hard and tough (as it is in nails)

Question 36

where is elastin found

Answer 36

in connective tissue, such as skin, blood vessels, and some ligament

Question 37

a change in one amino acids in the primary structure means what

Answer 37

a change in one amino acid may change the structure of the whole protein

Question 38

different protein have….

Answer 38

different sequences of amino acids in their primary structure