b1.2 proteins

Question 1

what are proteins

Answer 1

complex macromolecules composed of one or more chains of amino acids

Question 2

what roles do proteins have

Answer 2

structural support, catalysis and signalling pathways

Question 3

what are amino acids

Answer 3

monomers that are used to make proteins.

Question 4

how many unique amino acids are there

Answer 4

20

Question 5

structure of a amino acid

Answer 5

central carbon= alpha carbon
covalently bonded with a
carboxyl group (-COOH)
an amino group (-NH2)
a hydrogen atom (-H)
a unique organic side chain (R-group)

Question 6

how do amino acids join together

Answer 6

condensation reaction
a peptide bond is formed when (-COOH) of one amino acid and the amino group (-NH2) of another amino acid join) forming dipeptide (C-N) releasing water

Question 7

is the covalent bond strong

Answer 7

yes

Question 8

what does the N terminal represent

Answer 8

free amino group

Question 9

what does the C terminal represent

Answer 9

carboxyl group

Question 10

polypeptides

Answer 10

a chain of amino acids that is linked together by peptide bonds

Question 11

what is a essential amino acid

Answer 11

amino acids that your body cannot produce and therfore must be obtained by the food that you eat

Question 12

what are essential amino acids used for

Answer 12

maintenance and repair of body tissues

Question 13

non essential amino acids

Answer 13

Amino acids that can be produced by the body from other amino acids or by the breakdown of proteins.

Question 14

why is there an infinite variety of possible peptide chains

Answer 14

ability to combine the 20 different amino acids in any sequence. This allows for creation of an almost limitless number of unique proteins with different structures and functions.

Question 15

what is a protein

Answer 15

complex, three-dimensional structure that is made up of one or more polypeptide chains

Question 16

n protein composed of only 1 polypeptide chain

Answer 16

the amino acids will interact with each other, folding the chain into a functional protein.

Question 17

In proteins composed of more than one polypeptide,

Answer 17

the polypeptide chains can additionally interact with each other, contributing to the overall structure of the protein.

Question 18

denaturation

Answer 18

A process in which the structure of a protein is altered, causing it to lose function, usually permanently.

Question 19

2 factors that cause denaturation of proteins

Answer 19

proteins and PH

Question 20

what are all enzyme

Answer 20

proteins

Question 21

what happens with extreme changes in pH

Answer 21

in pH can affect protein solubility and shape by altering the protein’s charge. This can lead to irreversible changes in protein structure, causing inactivity.

Question 22

what do high temperatures cause for proteins

Answer 22

High temperatures can break the weak hydrogen bonds holding the protein structure together, causing the protein to unfold and lose function.

Question 23

what is the r group

Answer 23

R-group is what gives each amino acid its unique characteristics.

Question 24

Hydrophobic R-groups

Answer 24

are non-polar and tend to repel water molecules.

Question 25

Hydrophilic R-groups

Answer 25

are polar or charged, acidic or basic, and tend to attract water molecules.

Question 26

4 levels of protein structure

Answer 26

primary structure
secondary structure
tertiary structure
quaternary structure.

Question 27

primary structure of proteins

Answer 27

Structure of a protein that refers to the specific sequence of amino acids that are joined together to form a polypeptide chain.change in the sequence of amino acids may result in significant changes to the protein’s structure and function

Question 28

secondary structure of proteins

Answer 28

Structure of a protein that refers to the local folding patterns that occur within the polypeptide chain.
either:
alpha helices or beta pleates sheets
This is achieved through hydrogen bonding between the carboxyl group of one amino acid and the amino group of another amino acid in a different part of the polypeptide chain.
hydrogen bonds on their own are weak but become strong

Question 29

alpha helix

Answer 29

the hydrogen bond forms between the amine hydrogen of one amino acid and the carboxyl oxygen of another amino acid that is four residues away in the sequence

Question 30

beta pleated sheet

Answer 30

ections of the polypeptide chain run parallel to each other, and hydrogen bonds form between adjacent strands.

Question 31

tertiary structure of proteins

Answer 31

Structure that gives rise to the overall three-dimensional shape of the protein.

Question 32

what is the tertiary structure dependant on

Answer 32

It is dependent on the interaction between R-groups, which may include the formation of hydrogen bonds, ionic bonds, disulfide covalent bonds and hydrophobic interactions

Question 33

quaternary structure

Answer 33

links polypeptide chains to form a single large complex protein.

Question 34

protein structure os primary

Answer 34

has peptide bond and is linear

Question 35

secondary protein structure

Answer 35

peptide bond, hydrogen bond

Question 36

tertiary protein structure

Answer 36

peptide bond, hydrogen bond, disulfide bridge, ionic bond, hydrophobic interaction
into a fibrilor or globular structure

Question 37

what are fibrous proteins

Answer 37

structural roles in the body
long molecules
usually insoluble in water
have seconday structure with many a-helices with hydrogen bonds

Question 38

examples of fibrous proteins

Answer 38

collagen and keratin

Question 39

globular proteins

Answer 39

complex rounded 3 dimensional shape
either tertiary or quaternary structure
soluble in water
enzymes such as pepsin and antibodies

Question 40

examples of globular proteins

Answer 40

myglovbin and hemoglobin