Protein Structure Flashcards
The only form of protein structure not affected by denaturation?
Primary Structure
States that at least for a small globular protein in its standard physiological environment, the native structure is determined only by the protein’s amino acid sequence
Anfinsin’s Dogma
A paradox that arises since the native folded state of protein by a random search among all possible configurations can take an enormously long time yet proteins can fold in seconds or less.
Levinthal Paraxox
True or False. Most of the amino acids are a-amino acids
True. It means both amino and carboxyl groups are attached to the a carbon atom.
What amino acids has the largest side chain?
Tryptophan
Identify the branched-chain amino acids whose metabolites accumulate in MSUD
- Leucine
- Isoleucine
- Valine
What is considered to be the 21st amino acid?
Selenocysteine (Sec)
Considered the 22nd Amino Acid
Pyrrolysine (Pyl)
What are the essential amino acids ?
- Phenylalanine
- Valine
- Threonine
- Tryptophan
- Isoleucine
- Methionine
- Histidine
- Arginine
- Lysine
This is the only semi-essential amino acid
Arginine
Characteristic of a peptide bond
Has a partial double-bond character
Angle between the alpha carbon and the nitrogen
Phi Angle
Angle between the alpha carbon and the carbonyl carbon
Psi angle
This terminus contains targeting signals, that targets protein to a specific organelle
N-terminus
This terminus has retention signals for protein sorting , which keeps the protein in the endoplasmic reticulum
C-terminus
Part of a polypeptide that consist of a free -COOH structure
C-terminal
Which is the terminal ends of proteins that can be modified post translationally , most commonly by the addition of a lipid anchor that allows the protein to be inserted into a membrane without having transmembrane domain?
C-terminal
What do you call the supersecondary structures produced by packing side chains from adjacent secondary structural elements close to each other?
Motifs
What is the fundamental functional and three-dimensional structural units of polypeptide called?
Domains
These are specialized group of proteins required for the proper folding of many species of proteins
Chaperones
Porphyrins have a maximum characteristic electronic absorption spectrum around _________ nm known as the Sorek peak.
400nm
Factors that cause the hemoglobin curve to shift to the right.
- CO2 ⬆️
- Acidity ⬆️ (⬇️pH)
- 2,3-BPG ⬆️
- Exercise ⬆️
- Temperature ⬆️
When blood glucose enters the erythrocytes, it glycates which amino acid?
Lysine : Inc glycation of hgb noted in px with dm due to inc glucose in the blood
Hydroxylation of proline and lysine residues require which vitamin?
Vitamin C
Identify the most common type of Ehlers- Danlos syndrome
Hypermobility, other subtypes include classical and vascular.
This refers to the part of the antigen to which antibody binds
Epitope
This refers to the part of the antigen to which an antibody binds to the epitope of the antigen
Paratope
This class of enzyme cleaves substrate bonds using water (adding H+ or OH-) to the cleavage products.
Hydrolases
This class of enzyme catalyzes cleavage of C-C, C-S, and certain C-N bonds
Lyases
This class of enzyme catalyzes the formation of bonds between C and O, S, and N coupled to hydrolysis of high energy phosphates
Ligases (g for group)
This refers to the active enzyme + nonprotein component .
Holoenzyme
This refers to the enzyme without its nonprotein component
Apoenzyme
This refers to the nonprotein component that is a metal ion
Cofactor
This refers to the nonprotein component that is small and organic molecule
Coenzyme
True or False. Coenzymes are usually derived from minerals.
False, coenzymes are usually derived from vitamins.
Characteristic of a competitive inhibitor.
Increases apparent Km without affecting Vmax
Identify the type of enzymes that is regulated by molecules called effectors that bind noncovalently at a site other than the active site.
Allosteric Enzymes
Thyroid hormones production from thyroid glands
- Thyroxine (T4): 80-90%
- Triiodothyronine (T3): 10-20%
Identify the endopeptidases specific of the sites of basic AAs
Trypsin
Identify the endopeptidases specific at sites of neutral AAs
- Chymotrypsin
- Elastase
Identify the ectopeptidase specific at neutral AA at C- terminus
Carboxypeptidase A
Characteristic of binding of Oxygen by Hgb.
The O2 affinity of Hgb increases as the percentage saturation increases
The Oxyhemoglobin dissociation curve relates the ______ of oxygen in the blood to the _____ of hemoglobin with oxygen
Partial pressure; Percent saturation
Increases in CO2 levels lowers the pH of blood causing hemoglobin to release O2 to the body tissues. What is this phenomenon?
Bohr Effect
Removal of O2 from hemoglobin causes increase in affinity of hemoglobin for CO2 , allowing it to be expired into the lungs. What is this phenomenon?
Haldane Effect
This describes the exchange of bicarbonate and chloride across the membrane of the RBCs.
Chloride shift or Hamburger Effect
Each 1g of hemoglobin can maximally bind _____ ml of O2.
1.34mL
Any of these genes are mutated in Alport Syndrome
Type IV collagen genes (heterotrimers)
1. COL4A3
2. COL4A4
3. COL4A5
What are the hormones secreted by the anterior pituitary?
- TSH
- FSH
- LH
- ACTH
- GH
- Prolactin
(FLAG PT)
Which has a higher O2 affinity?
Adult Hgb or Fetal Hgb?
Fetal Hgb
Are enzymes nutritionally essential?
No
What amino acid is a major excitatory neurotransmitter?
Glutamate
What amino acid is a major inhibitory neurotransmitter?
Glycine
What amino acid is biosynthetic precursor to porphyrins in red blood cells ?
Glycine
What amino acid is most abundant in collagen ?
Glycine
What amino acid is used in lipid transport?
Lysine
Aspartame is composed of what amino acids? (3)
Phenylalanine
Methanol
Aspartic acid
