Proteins (CH 3.4) Flashcards

1
Q

What are the 7 job categories that proteins can fill?

A
  • Enzyme Catalysis
  • Defense
  • Transport
  • Support
  • Motion
  • Regulation
  • Storage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How will the protein complete it’s duty as Enzyme Catalysis?

A
  • Facilitate specific chemical reactions by stressing particular chemical bonds
  • They’re 3D, globular & fit snuggly around the molecules they act on
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How will the protein complete its duty in Defense?

A
  • They will be globular shaped
  • Use their shapes to “recognize” foreign microbes & cancer cells
  • Form the core of the body’s endocrine & immune systems
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How will the protein complete its duty in Transport?

A
  • They will be Globular shaped
  • Transport small molecules & ions
  • membrane transport proteins will help move ions & molecules across the membrane
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How will the protein complete its duty in Support?

A
  • Will be protein fibers= keratin in hair, fibrin in blood clots, collagen
  • If its collagen= will serve as matrix of skin/ ligaments/ tendons/ bones, Will be most abundant protein in vertebrate body
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How will the protein complete its duty in Motion?

A
  • Help in muscle contraction bc Actin & Myosin out here slidin
  • Contractile proteins= play key roles in cell’s cytoskeleton & moving materials within cells
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How will the protein complete its duty in Regulation?

A
  • Will be smaller proteins= hormones= intercellular messenger in animals
  • Turning genes off/on during development
  • Receive info= actin like surface cell receptors
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How will the protein complete its duty in Storage?

A

-Calcium & iron are stored in the body by binding as ions to storage proteins

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

What are proteins?

A
  • Linear polymers made w/ 20 different amino acids which contains an amino group & acidic carboxyl group
  • Composed of 1 or more unbranched chain (polypeptide)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What determines the protein’s structure & function?

A

-The specific order of amino acids

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

How do R groups effect Amino Acids?

A

-R groups determine the unique characteristic of each amino acid & the chemistry of them

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

What are the 5 Chemical Classes that the 20 amino acids are grouped into based on their R group?

A
  • NONPOLAR amino acids often have R groups that contain -CH2 or -CH3
  • POLAR charged amino acids have R groups that contain oxygen/ -OH
  • CHARGED amino acids have R groups that contain acids or bases that can ionize
  • AROMATIC amino acids are nonpolar, they contain R groups that have an organic (carbon) ring w/ alternating double & single bond
  • SPECIAL FUNCTIONS= SPECIAL PROPERTIES
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does an Amino Acid have once it’s ionized?

A
  • R group
  • Positive amino (NH3+) group at one end & a negative (COO-) group at the other
  • Both of these groups on a pair of amino acids have undergone dehydration reaction to form a covalent bond
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a Peptide bond?

A
  • Covalent bond that links 2 amino acids via dehydration reaction
  • Has partial double bond character which prevents amino acids to rotate around N-C linkage
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a Polypeptide?

A
  • Composed of amino acids linked by peptide bonds
  • An unbranched chain that when added with more forms a protein
  • A protein=polypeptide ONLY WHEN theres only 1 chain in a protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What kind of amino acids are inside nearly every protein?

A

-Nonpolar amino acids bc they’re shoved by water’s hydrophobic tendency to exclude nonpolar molecules

17
Q

What kind of amino acids are outside the protein?

A

-Polar & Charged amino acids

18
Q

What are the 4 Hierarchical levels of structure for a protein?

A
  • Primary
  • Secondary
  • Tertiary
  • Quaternary
19
Q

What is the Primary level of the structure of a protein?

A
  • Amino acid sequence
  • Any of the 20 amino acids might appear at any position= great diversity
  • A change to just one amino acid in a sequence will have drastic effects
20
Q

What is the Secondary level of the structure of a protein?

A
  • Hydrogen bonds forming between nearby amino acids

- Produces 2 different structures= Alpha-Helices & Beta-pleated sheets

21
Q

What is the Tertiary level of the structure of a protein?

A
  • Final folded shape via hydrophobic exclusion
  • But folding is determined by the chemical nature of its side groups
  • Determines how regions of 2ndary structure are further folded in space to form the final shape of the protein
  • Last step for proteins with only a single peptide chain
22
Q

How is the Tertiary structure stabilized?

A
  • By forces including H bonding between R groups of different amino acids
  • Electrostatic attraction between R groups w/ opposite charge (salt bridges)
  • Hydrophobic exclusion of nonpolar R groups
  • Covalent bonds in the form of disfulfides
  • Also strongly influenced by how well it fits together
23
Q

What are Disfulfides bonds?

A

-Covalent links between 2 cysteine R groups

24
Q

What is the Quaternary level of the structure of a protein?

A
  • Only found in proteins w/ 2 or more polypeptides

- Final structure of the protein is the arrangement of the multiple polypeptides in space

25
Q

What are Motifs?

A
  • Similar structures between dissimilar proteins
  • Useful in detemining the function of unknown proteins
  • “Words/ phrases”
26
Q

What are the 3 common Motifs?

A
  • Beta-Alpha-Beta= creates a fold/ crease= Rossmann fold at the core of nucleotide-binding sites in a wide variety of proteins
  • Beta Barrel= Beta-Sheet folded around to form a tube
  • Helix-Turn-Helix= 2 Alpha helices separated by a bend =used to bind to the DNA double helix
27
Q

What are Domains?

A

-(of proteins) Are functional units within a larger
structure
-Can be thought of as substructure within the tertiary structure= “Paragraphs”
-Multiple Domains that make up most proteins perform different parts of the protein’s function
-Can be physically separated
-Can help proteins fold into its proper shape
-Correspond to the structure of genes & encode them

28
Q

What are Chaperone Proteins?

A
  • Located inside cells & helps other proteins fold correctly
  • Many= Heat shock proteins which are produced in large amounts in response to elevated temperature bc high temp causes proteins to unfold
  • Chaperonin= a class= super flexible, folding process within harnesses hydolysis of ATP to power these changes in structure necessary for function
29
Q

What would happen if there are Chaperone Protein deficiencies?

A

-Can be implicated in diseases bc key proteins aren’t folded correctly

30
Q

What is Denaturation?

A

-The protein’s shape changing or unfolding completely as a result of the protein’s environment being altered

31
Q

How can proteins be denatured?

A

-When the pH, temperature, or ionic concentration of the surrounding solution changes

32
Q

What are do denatured proteins do?

A

-Are usually biologically inactive= significant in the case of enzymes

33
Q

What is Renaturation?

A

-When a protein’s normal environment is reestablished after denaturation, a small protein may spontaneously refold into its natural shape

34
Q

What is Dissociation?

A

-When the subunits of proteins of the 4tnary structure separate WITHOUT losing their 3tiary structure

35
Q

What is the general structure of an Amino Acid?

A
  • Has central carbon= C-alpha
  • Has an amino group on one side of c-alpha
  • Has carboxylic acid on the other side of c-alpha
  • And has a side chain/ R group attached to c-alpha
  • This structure serves as the backbone for all 20 amino acids