Proteins Flashcards
the functional groups
amine group and carboxyl group
how many amino acids in a protein
20
what is L vs D
L/levo: amine group on the left;
D/dextro: amine group on the right
what is a peptide bond; what type
amine group to carboxyl; covalent
what is the first amino acid of all proteins
aug
monomers of proteins
amino acid
when you digest proteins what process breaks them down into amino acids
hydrolysis
2 amino acid
dipeptide
oligopeptide
3-10 amino acids
more than 10 amino acid
polypeptide
the type of most proteins (# of amino acids) and how many they typically have
polypeptide; 350
how many essential AA
10
how many nonessential AA
10
how do we get essential AA
must be eaten
how do we get nonessential AA
we make them
how many proteins in a cell and how long they last
1 billion; about a week (we are constantly making them)
what are the 4 types of R groups
basic, acidic, polar, nonpolar
name the basic R groups
lysine, arginine, histidine
what makes an R group basic
positive charge
how to help recognize a basic R group
NH
name the acidic R groups
aspartic acid, glutamic acid
what makes an R group acidic
neg charge (donate protons)
how to recognize an acidic r group
C double bonded to O and bonded to O
how to recognize an uncharged polar R group
OH
charge of polar R groups
neutral
how to help recognize a nonpolar R group
CH
charge of nonpolar R group
neutral
what allows for the “mirror image” isomers
the alpha carbon is asymmetric
types of protein functions: enzyme
speeds up chemical reaction (by catalyzing covalent bond breakage or formation)
types of protein functions: structural protein
holds up (provides mechanical support)
types of protein functions: transport protein
carries small molecules or carbons;
example: hemoglobin carries oxygen
types of protein functions: motor protein
slide filaments (generates movement)
types of protein functions: storage protein
stores small molecules
signal protein
tells cells to ______ (carries signals between cells)
types of protein functions: receptor proteins
detects signals (and transmits them)
types of protein functions: gene regulatory protein
switch genes on/off (p53)
types of protein functions: special purpose proteins
varied
how many AA commonly found in proteins
20
what process do AA bond
dehydration synthesis
what causes proteins to fold; and what is it based on
R groups; charge
what form are most proteins in
globular (folded)
what decided the shape of a protein
AA sequence
what are the four noncovalent forces found in protein folding
ionic bonding, hydrogen bonding, VanDer Wahls forces, hydrophobic interactions
ionic bonding
positive to negative
hydrogen bonding
positive hydrogen to negative oxygen
VanDer Wahls forces
atoms forced close to each other (weak)
hydrophobic interactions
they turn in to avoid water
what is the primary level of protein structure
amino acid sequence (always!)
what is the secondary level of protein structure
common folding patterns
what are the common folding patterns in the secondary level or protein structure
- alpha helix- “slinky”
2. beta sheet- “elongated slinky”
what is the tertiary level of protein structure
3-D shape (final)
what is the quarternary level of protein structure
more than 1 polypeptide (1 protein, multiple polypeptides)
conformation
overall, final 3-D shape (use x-ray diffraction)
native protein
normal, natural state
denatured
lost its shape
what are the 2 factors that can denature a protein
temperature, pH-isoelectric point
why does temp denature
hotter, breaks weak bonds, changes shape
isoelectric point
pH at which a protein becomes neutral
negative has _____ isoelectric points
low
positive have _____ isoelectric points
high
components of enzymes
- most* are proteins (*rna)
- shape is important
- specific
- not changed, used repeatedly
enzyme equation
E+S–>ES(noncovalent bond here)–>EP–>E+P
what are E, S, and P
Enzyme, substrate, product
what happens to the substrate
it is altered permanently (into the product)
what enzyme would digest a fat
lipase
at high temps the rate of enzyme action decreases because
the increased heat alters the site of the active enzyme
enzymes influence chemical reactions in living systems by
affecting the rate at which reactions occur
which group of organic compounds includes enzymes
proteins
what does the lock and key hypothesis attempt to explain
mechanism of enzyme specificity
a substance acted upon by an enzyme
substrate
enzymes are
specific
at 0°C most enzymes are
inactive
what enzyme is in maltase but not maltose
nitrogen
what is an environmental condition that has the LEAST effect on the rate of enzyme controlled reactions
light present
lipase, maltase, and protease are examples of
enzymes
