Proteins Flashcards
A _____ bond is specific to the amide bond in proteins
peptide
A peptide bond is between the ____ group of one amino acid and the ____ group of another amino acid
carboxyl (COO-), amino (NH3+)
____ is released during a peptide/amide bond formation
water
The byproduct of a peptide bond formation is a _______
dipeptide
A dipeptide has a ___ end and ____ end
N-terminal, C-terminal
The backbone of a dipeptide is repeated _________ units with R side chains
N-C alpha-C
The atoms around a peptide bond (CO-NH) are _______
coplanar (2D)
_____ is the enzyme that breaks down RNA molecules
ribonuclease
The R side chain of the protein is ______
hydrophobic
The inside of a protein is ______
hydrophillic
______ is a protein that attacks bacterial cell walls
lysosine
Every copy of the same protein follows ____ folding patterns
the same
Proteins have ____ numbers of chains and disulfide bonds
varied
The most abundant protein in humans (25-30% of all proteins) is _____
collagen
Collagen is ____ shaped
fibrous
Collagen is 1/3 ____ and is rich in _____
glycine, proline
A phylogenetic tree compares amino acid sequences of the protein ________
cytochrome C
On a phylogenetic tree, amino acid _____ are on the branches
changes
_____ proteins require something bound to them to activate
conjugated
The binding of nonprotein groups affect protein _____
folding
Glyco means ____
carbohydrate
Lipo means _____
lipid
Nucleo means _____
DNA or RNA
Metallo means _____
metal ion
Ribonuclease and trypson are examples of what protein function?
enzymes (catalyst)
Insulin, trans factor NF-1 are examples of what protein function?
regulatory
Hemoglobin and glucose transporter and examples of what protein function?
transport
casein and ovalbumin are examples of what protein function?
storage
casein and ovalbumin are examples of what protein function?
storage
actin, myosin, and tubulin are examples of what protein function?
contractile/motile
Collagen and a-keratin are examples of what protein function?
structural
Immunoglobulins and fibrinogen are examples of what protein function?
protective
Antifreeze and glue proteins are examples of what protein function?
exotic
_____ separates ions on the basis of charge
chromatography
____ ____ ______ separates ions on the basis of size
size exclusion chromatography
_____ _______ separates ions on the basis of affinity (specific binding to small molecules)
affinity chromatography
_____ is the movement in an electric field
electrphoresis
______ separates ions on the basis of molecular weight
SDS-PAGE (SDS-polyacrylamide gel electrophoresis)
____ _____ separates ions on the basis of isoelectric point (pl)
isoelectric focusing
pl is a measure of the ____ of the side chain
pH
____ ___ ____ ______ separates ions on the basis of isoelectric point and molecular weight (added)
two dimensional gel electrophoresis
___ protein shape is linear molecules that serve structural roles
fibrous
____ protein shape is a cluster of hydrophobic amino acid insides and hydrophilic amino acid outsides
globular
_____ protein shape interacts with membrane lipids and has hydrophobic amino acids on the outside
membrane
collagen is an example of what protein shape?
fibrous
myoglobin is an example of what protein shape?
globular
bacteriorhodopsin is an example of what protein shape?
membrane
What is the first level of protein structure?
primary
What is the second level of protein structure?
secondary
What is the third level of protein structure?
tertiary
What is the fourth level of protein structure?
quartenary
_____ structure is the amino acid sequence of a protein
primary
_____ structure is the short range structure in a protein, either alpha helix or beta strand
secondary
____ structure is the folding of a polypeptide into it’s 3D shape
tertiary
_____ structure is the numbers and kinds of polypeptide subunits in a protein
quaternary
_____ structure forms the polypeptide backbone
secondary
______ structure is the spatial arrangement of polypeptide chains
quaternary
Ribonuclease is roughly ____ a.a. long
124
_____ ____/______ are amino acid sequences used repeatedly in a single protein or that are found in different proteins
protein domains/modules
Protein domains/modules are typically ____ to ____ amino acids long
40-100
Protein domains do/do not have the same function in different proteins
do not
What type of protein domain is unusual and less common?
different proteins
Domains in _____ occur from faulty DNA replication
the same protein
Domains in ____ occur after the insertion of a copy of a DNA segment into another gene
different proteins
Some domains are ____ and their function is unknown
neutral
Domains ____ over time and become unrecognizable to the original
mutate
A newly synthesized protein first forms segments of ____ _____
secondary structure (alpha helix, beta sheets)
____ bonding occurs along segments of polypeptides and between segments
H
Secondary structure of polypeptides arrange into a ______ shape by hydrophobic interactions
globular
Secondary structure of polypeptides arrange into a globular shape by _______
hydrophobic interactions
Hydrophobic R side chains want to cluster where?
away from water, middle of protein
Can secondary structure change during the generation of the tertiary structure?
yes
Protein folding may need to assistance of ____ _____
molecular chaperones
What is the role of molecular chaperones?
proteins in cell, bind to the new protein and bring parts together to obtain proper 3D folded
Do all proteins need molecular chaperones?
no
___ ____ are misfolded, insoluble, and aggregated proteins in brain cells
amyloid deposits
What protein is misfolded in Alzheimer’s disease?
amyloid-b
What protein is misfolded in Parkinson’s disease?
a-synuclein
____ _____ are protein subunits that combine to form multi-subunit complexes
Quaternary structures
Proteins can have either ____ subunits or _____ types of protein chains
identical, different
The ______ produces quaternary structure are the same as those used for tertiary structure
forces
What 4 things play a role in quaternary structure production?
hydrophobic interactions, hydrogen bonding, ionic interactions, disulfide bonds
Quaternary structure allows for _____ _____ between protein subunits
cooperative behavior
In hemoglobin, there are ____ protein subunits
4
How does hemoglobin exhibit cooperative behavior?
The binding of the first O2 molecule makes it easier for the other 3 O2 molecules to bind to the protein subunits
Hemoglobin aides in what physiological function?
rapid release of O2 into lungs
What are the two types of quaternary structure?
fixed number, open
What are microtubules?
long, hollow tubes
Where are microtubules found?
cytoskeleton (cell structure), mitotic spindles (cell division process)
Tubulin dimers _____ to form microtubules
polymerize
Microtubules are dynamic and can easily ______
increase or decrease in length
Microtubules have ____ quaternary structure
open