Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Biology > Proteins > Flashcards

Proteins Flashcards

(59 cards)

Start Studying
1
Q

Chain of amino acids

A

Polypeptide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Tertiary structure

A

Twisted around

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Different groups in amino acid structure

A

NH2 = amine group
R = R group (side chain)
CO2H = carboxyl group

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Charges of groups and how they are held together in the secondary structure

A

-NH and -C=O on the ends of the chain
H = overall positive charge
O = negative charge
Opposite charges attract
2 groups form weak hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Amino acid structure

A

N - C - C in middle

N attached to 2 hydrogen
C attached to R and H
C attached to H on top and O=H on bottom

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How do the weak hydrogen bonds affect the secondary structure of the protein

A

Cause long polypeptide chain to be twisted into an alpha helix coil

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Process called in which many amino acid monomers can be joined together

A

Polymerisation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Primary structure

A

—————-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the primary structure determine in the protein

A

Ultimate shape and function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Quaternary structure

A

Large number of proteins linked together, lots of twisted chains

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is a peptide bond formed

A

Combining the carboxyl group with an -H from another amino acid is lost
2 amino acids become linked when water is removed
Forming a peptide bond between amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

3 bonds in tertiary structure

A

Disulfide bond = strong
Ionic bonds = between carboxyl and amino groups, weak
Hydrogen bonds = weak

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Secondary structure

A

VVVVV——-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the reaction called with the removal of water

A

Condensation reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Test for proteins

A

1) Place sample in test tube and add equal volume of sodium hydroxide solution
2) Add few drops of dilute copper solfate and mix
3) Purple = presence of peptide bonds, so presence of protein
Blue = no presence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is changed among different amino acids

A

Their side group differs (R group)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Reaction that forms dipeptides and polypeptides

A

Condensation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Difference between dipeptide and polypeptide

A

Dipeptide = 2 amino acids
Polypeptides = many amino acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are fibrous proteins for

A

Structural function

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What do globular proteins do

A

Metabolic functions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Describe fibrous proteins structure

A

Long chains which run parallele to one another
Linked by cross-bridges forming stable molecules

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Describe each of the stages when forming a quaternary protein

A

1) Primary = sequence of amino acids determining protein’s shape and function
2) Secondary = polypeptide chain twisted into alpha helix due to hydrogen bonding because of different charges in amino acid
3) Tertiary = polypeptide helix twisted into compact structure with bonds disulfide, hydrogen, ionic
4) Quaternary = Many different polypeptide chains forming protein molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What type of chains can be contained in the quaternary structure of the protein formed

A

both protein and non-protein groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What is chromatography

Study These Flashcards
A

Technique to separate a mixture into its individual components
Relies on differences in solubility with different attractions to the mobiel and stationary phase

25
Method of paper chromatography with amino acids
1) Use paper chromatography to separate amino acids 2) Spot placed on line at bottom of paper 3) Spots of known standard solutions placed on line beside unkown sample spot 4) Chromatography paper suspended in solvent 5) Amino acids separate depending on their charge and size 6) Compare unkown to known and math with chromatograms
26
What are the two shapes that can form due to the secondary structure of a protein
Alpha helix Beta pleated sheet
27
Differencebetween alpha helix and beta pleated sheet
Alpha = H2 form every fourth peptide Beta = protein folds so two parts of the polypeptide are parallel so H2 form between parallel peptide bonds
28
How can hydrogen bonds break
High temps and ph changes
29
What structure do the two types of proteins have
Fibrous protein = secondary Globular protein = tertiary
30
What bonds do secondary have
Peptide and hydrogen
31
What bonds do primary have
Peptide
32
What bonds do tertiary hav
Peptide hydrogen disulphide ionic and hydrophobic interactions
33
Describe disfulfide bonds
Strong covalent Form R groups Disulfide bridges strongest but occur less frequently Stabilise proteins Broken by reduction
34
Describe ionic bonds
Form between NH3+ and COO- when water removed Ionic bonds are stronger than hydrogen bonds but not common Broken by pH changes
35
Describe h ydrogen bonds
Form between strong polar R group Most common but weakest
36
Hydrophobic interactions
Non-polar R groups within interior of proteins
37
Name of protein test
Biuret test
38
Describe globular proteins
Compact, spherical, soluble in H2O
39
Why are globular proteins spherical
Non polar hydrophobic R group orientate towards centre of protein and polar hydrophilic R group orientates to outside
40
How are globular proteins fit for their role
Orientation = water molecules can surround polar hydrophilic R group Solubility = can be easily transported around organisms for metabolic reactions Folding = enzymes and immunoglobins Conjugated = contain prosthetic group
41
Describe fibrous proteins
Long strands of polypeptide chains that have cross linkages due to H2 bonding Little or no tertiary structure
42
Why are fibrous proteins fit for their role
Insoluble = larhe number of hydrophobic R groups Organised = highly repetitive Good for structure e.g. collagen
43
Compare globular and fibrous proteins
SHape: G is circular, F is long strands AMino acid sequence: G is irregular and wide range of R groups, F is repetitive with limited range of R groups Function: G is metabolic/ functional, F is structural G is haemoglobin, enzymes, immunoglobulin, insulin. F is collagen, keratin, myosin, actin, fibrin Solubility: G is soluble, F is insoluble
44
What is collagen
Most structural protein found in vertebrates
45
What does collegen form
Tendons cartilage ligaments bones teeth skin walls of blood vessels cornea on eeye
46
Describe collagens structure
-Triple helix = 3 polypeptide chains held together close by H2 bonds -Glycine = every third amino acid is glycine, contains H atom found inside polypeptide chains to form tight triple helix -Fibrils = covalent bonds cross link R groups interacting triple helices when they are arranged parallele ot eachother -Fibres = fibrils arranged together form fibres
47
Collagens function
-Flexible structural protein form connective tissue -H2 bonds in triple helix = very strong, withstand large pulling forces without stretching or breaking -Staggered ends in fibrils = strength -Stable = lots of proline and hydroxyproline amino acids so more stable as R groups repel eachother -Length of collagen = too long to dissolve in water
48
Uses of amino acids
Protein synthesis/ Building polypeptides Respiration
49
How does the secondary structure determines the proteins overall structure
H2 bonding between C=O and NH every 4 amino acids along the chain Protein forms a righ thanded alpha helix A beta pleated sheet forms by folding the chain back on itself in a zig zag plane Both extend its 3D shape
50
What is a prosthetic group
Non amino acid section of a protein Covalently bonded to the polypeptide sections
51
Describe haemoglobins structure
4 separate polypeptide chains bonded together Each polypeptide bonded to a haem group which binds to O2
52
Beneits of haemoglobins structure in mammals
Function = bind to O2 in lungs and release O2 at respiring tissues Binding of O2 to one haem increases affinity of haemoglovin for O2 Changing shape of whole protein makes it easier to bind another O2 and harder to unbind Haemoglobin can deliver O2 readily to tissues that require it most
53
Define “r” group
Functional group
54
If an amino acid is non-polar where will it be in a globular protein
Centre Non-polar amino acids are hydrophobic and polar ones at the surface (in contact with water)
55
Why is a sickle cell less soluble
Non plar amino acid at surface Non polar do not interact with water
56
How are dipeptides formed
Two amino acids joined by peptide bond Condensation reaction occurs forming peptide bond Between amine and carboxylic group of adjacent amino acids
57
How are functional proteins different from a polypeptide
Polypeptide chains are primary structures Functional proteins are formed from more than one polypeptide chains Functional protein has tertiary or quaternary structure with hydrogen, ionic and disulfide
58
How is a polypeptide formd
Condensation between many amino acids
59
Why are cellular enzymes made from proteins
Shape relates to function Structure determines by primary structure Primary structure folds into tertiary which has a 3D shape Shape of primary determines by bonds occur between amino acids within primary sequence Bonds inclue hydrogen, ionic, disulfide Order of amino acids changed affects bonds between amino acids altering the shape

Biology (57 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions