Biochemistry Chapter 4

Question 1

Classification of proteins based on overall shape and protein, name the two kinds

Answer 1

Fibrous

Globular

Question 2

Fibrous Protein

Answer 2

Elongated in shape, extracellular proteins and provides mechanical strength to cell and are insoluble in water

Question 3

Globular protein

Answer 3

Globular proteins have more compact roundish shape, usually water soluble (eg many enzymes)

Question 4

Examples of fibrous protein

Answer 4

Keratin (hair), myosin (connective tissue) tropomyosin,

Question 5

What dictates how a protein will fold?

Answer 5

Chemical nature of side chain (is it polar or non polar) and the local environment (ie is it a polar or non polar solvent)

Question 6

Examples of Polar solvent versus non polar

Answer 6

Polar: water. Non polar-Chloroform

Question 7

Organization of proteins

Answer 7

Primary
Secondary
Tertiary
Quaternary (Not present in all proteins)

Question 8

Primary Sequence (structure) of proteins

Answer 8

Dictates the secondary structure and All proteins have this

Question 9

Secondary structure is the ____total of

Answer 9

All proteins have this, requires NMR and crystallography to determine

Question 10

Tertiary Protein structure

Answer 10

All proteins have this, requires NMR and crystallography to determine

Question 11

Quaternary structure

Answer 11

Only multi-subunit proteins have this structure

Question 12

A multi-subunit protein with quaternary structures consists of

Answer 12

multiple polypeptide chains

Question 13

Condensation reaction, to join two things…you have to remove

Answer 13

water

Question 14

condensation reaction is also called the _____ reaction or _____synthesis

Answer 14

dehydration

Question 15

Peptide bond, also called an _____ bond is formed between the a(- nitrogen atom of one amino acid and the carbonyl carbon of a second.

Answer 15

amide

Question 16

Leucine has a hydro___ side chain

Answer 16

phobic

Question 17

N-terminus is:

Answer 17

the end chain of the amino acid that is an Amino terminal residue (look for the NH3+ bond)

Question 18

C terminus is:

Answer 18

Carboxyl terminal residue (look for the C=OO bond

Question 19

Peptide is a very _____ ____ amino acids

Answer 19

short sequence of 8-10

Question 20

Protein chain or polypeptide chain, it is usually ___, or ___ or even ____ amino acids

Answer 20

100, 200 or 1000

Question 21

_____ is the largest protein

Answer 21

Titin

Question 22

Titin

Answer 22

has a kinase domain for signaling and also functions mechanically as a molecular spring to provide muscle with elasticity, allow postcontraction recovery, and prevent overextension

Question 23

1 Dalton = weight of One ___ atom

Answer 23

Hydrogen

Question 24

Molecular weight of 1 amino acid= _____ g mol -1 which equals ____ Dalton.
1000 Dalton = ___kDa

Answer 24

110
110
1 (kilo Dalton)

Question 25

Different combinations of polypeptide chains formed = 20^n, where n is the number of ___ ___ involved in building a polypeptide chain

Answer 25

amino acids

Question 26

Linear polypeptide chain can be cross linked by _____ crosslinks

Answer 26

disulfide

Question 27

Oxidation to create a new bond results in a loss of ____

Answer 27

hydrogens

Question 28

Reduction of a chemical is the gaining of_____ to break apart the bond

Answer 28

hydrogens

Question 29

Cysteine is the ______ form, as ____ atoms are attached

Answer 29

Reduced | Hydrogen

Question 30

Cystine is the ______ form, due to the new bonding and loss of ____

Answer 30

Oxidized | Hydrogens

Question 31

Protein modification (Oxidation-reduction reactions) take place in the _____ _____

Answer 31

rough ER

Question 32

Inside the cell, the cytoplasm is very ___ so you will never have oxidation there, as oxidation would take place inside a compartment

Answer 32

Reducing

Question 33

You will never find ____ bonds in the soluble part of the cytoplasm

Answer 33

disulfide

Question 34

The first protein to be sequenced is___

Answer 34

insulin

Question 35

_____bonds help to modify protein and fold proteins so that it can function properly

Answer 35

Disulfide

Question 36

Protein ___ plays a major role in the function of a protein

Answer 36

modification

Question 37

Peptide bonds have _____ double bond characteristics that prevents ___ about the peptide bond. It is also uncharged, allowing formation of globular structures

Answer 37

partial | rotation

Question 38

Peptide bonds are: - Planner - ____ - Partial double bond characteristics - Very rigid

Answer 38

Uncharged

Question 39

Peptide bonds in proteins are almost always _____, as steric hindrance would prevent it from being cys as the side chains of the amino acids can be very bulky

Answer 39

trans

Question 40

Bond between the alpha carbon and the Nitrogen (amino) is the ____

Answer 40

phi (a circle with a line through it)

Question 41

Bond between the alpha carbon and the Carbon (carbonyl) group is the ___

Answer 41

Psi (Looks like a cactus or a trident)

Question 42

If the rotation is in a clockwise rotation it is represented by a ____ value. and if it is rotating in an anti clockwise rotation it is represented by a ____ value

Answer 42

Positive (+) negative (-)

Question 43

Hydrogen bonding scheme for Alpha Helix formula is: Carbonyl group of amino acid (n) forms Hydrogen- bond with NH(Amino) group on the (n + ___) amino acid on the ____ strand. Only one strand is involved in Alpha Helix!

Answer 43

4th SAME

Question 44

If you see a rod shaped protein chain, it is called an _____ _____

Answer 44

alpha helix

Question 45

Valine, Threonine and isoleucine can not be in an alpha helix due to _____at the beta carbon

Answer 45

branching

Question 46

Serine, Aspartate and asparagine can not be in an alpha helix due to side chains containing ____ donors and acceptors very close to the main chain

Answer 46

Hydrogen

Question 47

Proline can not be in an alpha helix as it lacks an NH group and ____ alpha helix. It has a ____ ring structure and cannot assume the phi value to fit into a helix

Answer 47

breaks rigid

Question 48

Due to Prolines rigid ring like structure, nature uses Proline to form a ____ in the structure of a protein

Answer 48

bend/fold

Question 49

Determining direction of helix, look at if the "screw"and ______ from the top, is it going clockwise or anti-clockwise.

Answer 49

tracing

Question 50

Alpha helix that are ____ handed are more common

Answer 50

right