Topic 1 Proteins Flashcards
(50 cards)
1
Q
- Contain carbon, hydrogen, oxygen, and nitrogen atoms (CHON)
- Combine to form amino acids
- Polymers of amino acids joined by peptide bonds
A
Protein
2
Q
- Link together to build polypeptides (or proteins)
- The monomers of proteins and have the structure below:
- There are 20 different amino acids, each with a different “R” group
A
Amino Acids
3
Q
- Refers to all the proteins expressed by one type of cell under one set of conditions
A
Proteome
4
Q
- Polymers of amino acids that are joined by peptide bonds through dehydration (condensation) reactions
- Becomes an amino acid chain that contains two end terminals on opposite sides
A
Polypeptides
5
Q
- (amino terminus) the side that ends with the last amino acids amino group
A
N-terminus
6
Q
- (carboxyl terminus) the side that ends with the last amino acids carboxyl group
A
C-terminus
7
Q
- Sequence of amino acids
A
Primary Protein Structure
8
Q
- Intermolecular forces between the polypeptide backbone due to hydrogen bonding
- Forms alpha helices and beta pleated sheets
A
Secondary Protein Structure
9
Q
- Tree-dimensional structure due to interactions between R-groups
- Can create hydrophobic or hydrophilic spaces based on the R-groups
- Disulfide bonds are created by covalent bonding between the R-groups of two cysteine amino acids
- Non-covalent interactions: H-bonds, ionic bonds, hydrophobic effect, and Van Der Waals forces
A
Tertiary Protein Structure
10
Q
- Multiple polypeptide chains come together to form one protein
A
Quaternary Protein Structure
11
Q
- Not water soluble
- Dominated by secondary structure
- Made of long polymers
- Maintain and add strength to cellular and matrix structures
A
Fibrous/Structural Quaternary Protein Structure
12
Q
- Water soluble
- Dominated by tertiary structure
- Enzymatic, hormonal, inter and intracellular storage, transport, osmotic regulation, immune response
A
Globular Quaternary Protein Structure
13
Q
- Proteins that function as membrane pumps, channels, or receptors
A
Intermediate Quaternary Protein Structure
14
Q
- Amino acids only
- Albumins and Globulins
- Scleroprotein
A
Simple Protein Composition
15
Q
- proteins that act as carriers or enzymes
A
Albumins and Globulins
16
Q
- fibrous proteins (I.e. collagen)
A
Scleroprotein
17
Q
- simple protein + non-protein
- lipoprotein
- mucoprotein
- chromoprotein
- metalloprotein
- nucleoprotein
A
Conjugated Protein Structure
18
Q
- bound to lipid
A
Lipoprotein
19
Q
- bound to carbohydrate
A
Mucoprotein
20
Q
- bound to pigmented molecule
A
Chromoprotein
21
Q
- complexed around metal ion
A
Metalloprotein
22
Q
- contains histone of protamine, bound to nucleic acid
A
Nucleoprotein
23
Q
- Describes the loss of protein function and higher order structures
- Reversed back to primary structure
- Implies that all of the information needed is encoded in its primary structure
A
Protein Denaturation
24
Q
- High or low temperatures
- pH changes
- Solvent
A
Proteins denature due to
25
Example: cooking eggs in high heat will disrupt the intermolecular forces in the egg’s proteins, causing it to coagulate
Protein Denaturation
26
- Eliminates whole protein structure including primary
Protein Digestion
27
1. storage
2. hormones
3. receptors
4. motion
5. structure
6. immunity
7. enzymes
Protein Functions
28
- Reserve of amino acids
Storage
29
- Signaling molecules that circulate through the body to regulate physiological process
Hormones
30
- Proteins in cell membranes, which bond to signal molecules to trigger changes inside cells
Receptors
31
- Movement generation for individual cells or entire organisms
Motion
32
- Provide strength and support to tissues
Structure
33
- Prevention and protection against foreign invaders
Immunity
34
- Act as biological catalysts by binding to substrates (reactants) and converting them into products
Enzyme
35
- Increase reaction rates by lowering the activation energy of a reaction
- The transition state is the unstable conformation between the reactants and the products
- Catalysts reduce the energy of the transition state
- Do not shift a chemical reaction of affect spontaneity
Catalyst
36
- Act as catalysts by binding to substrates (reactants) and converting them into products
- Bind to substrates at an active site, which is specific for the substrate that it acts upon
- Most enzymes are proteins
- Protein enzymes are susceptible to denaturation. They require optimal temperatures and pH for function
- Catalyze reactions in forward and reverse directions
- Do not change the spontaneity of a reaction
- Almost always considered proteins, but RNA can act as an enzyme
Enzyme
37
- Measures how efficient and enzyme is at binding to the substrate and converting it to a product
Specificity Constant
38
- Describes how the active site molds itself and changes shape to fit the substrate when it binds
- The “lock and key” model is an outdated theory of how substrates bind
Induced fit theory
39
- RMA molecule that can act as an enzyme (a non-protein enzyme)
Ribozyme
40
- Non-protein molecule that helps enzymes perform reactions by donating or accepting components
- Organic cofactor (i.e. vitamins): coenzyme
- Inorganic cofactors are usually metal ions
Cofactor
41
- Enzymes that are bound to their cofactors
Holoenzyme
42
- Enzymes that are not bound to their cofactors
Apoenzymes
43
- Cofactors that are tightly or covalently bonded to their enzymes
Prosthetic groups
44
- Occurs when a competitive inhibitor competes directly with the substrate for active site binding
- The rate of enzyme action can be increased by adding more substrate
Competitive Inhibition
45
- Occurs when the noncompetitive inhibitor binds to an allosteric site that modifies the active site
- In noncompetitive inhibition, the rate of enzyme action cannot be increased by adding more substrate
Noncompetitive inhibitor
46
- Location on an enzyme that is different from the active site
Allosteric site
47
- Can be used to visualize how inhibitors affect enzymes
Enzyme kinetics plot
48
Terms used to describe the plot:
- The x-axis represents substrate concentration [X]
- The y-axis represents reaction rate or velocity (V)
- Vmax is the maximum reaction velocity
- Michaelis Constant (KM) is the substrate concentration [X] at which the velocity (V) is 50% of the maximum reaction velocity (Vmax)
- Saturation occurs when all active sites are occupied, so the rate of reaction does not increase anymore despite increasing substrate concentration (causes graph plateaus)
- Competitive inhibition: Km increases and Vmax stays the same
- Noncompetitive inhibition: Km stays same while Vmax decreases
Enzyme kinetics plot
49
- Determined by substrate and enzyme concentration, temperature, pH, and presence/absence of inhibitors
Efficiency
50
- Catalyzes reactions that break the alpha-glycosidic bonds in starch
Amylase
