Proteins Flashcards
Made up of amino acids that are joined together by ___
Peptide bonds
There are __ naturally occurring amino acids
20
Most genetic information directs the synthesis of protein
Central Dogma
__ properties of amino acids that play an important role in their ___
Chemical , Function
8 Functions of Proteins
Structure Catalysts Movement Transport Hormones Protection Storage Regulation
Protein function that is constituent of the skin, bone and hair
Structure – Keratin and collagen
2 properties of collagen and keratin that is attributed to their role
Fibrous – Hydrophobic
Protein function that hastens all reactions in the living system
Catalyst
Protein that hastens all metabolic reactions
Enzymes
Example of roles of enzyme in the body
Conversion of Alcohol by alcohol dehydrogenase
Digestion of carbs by salivary amylase
For blood clotting
Muscle contraction
Protein Function governed by muscle proteins
Movement – Myosibn and Actin filaments
Protein function chiefly done by hemoglobin
Transport
Protein function done by fibrinogen and antibodies
protection
Protein function with examples of insulin, oxytocin, and human growth hormone
Hormones
Protein function with examples of Casein, ovalbumin and ferritin
Storage
Protein function storage (Analogy)
Casein : ___
Ovalbumin : ____
Ferritin : ____
Casein : milk
Ovalbumin : eggs and nutrients of newborn
Ferritin : Iron
Protein Function that controls when the expression of genes should take place
Regulation
2 Types of proteins
Globular and Fibrous proteins
Predominant type of protein
Globular protein
type of protein for structural purposes
fibrous protein
type of protein that have a characteristic of elongated wires
Fibrous proteins
type of protein that is insoluble in water and have high percentage of secondary structure – alpha helix and beta pleated sheets
Fibrous protein
Type of protein that is the vast majority of all known enzymes
Globular protein
Predominant type of protein
globular protein
Type of protein that forms colloid with water
globular protein
type of of protein that is spherical in shape
globular protein
Building blocks /monomer unit of protein
amino acid
Compound that contains both the amino group and carboxyl group
amino acid
An amino acid in which the amino group is on the carbon adjacent to the carboxyl group
Alpha amino acid
Alpha amino acids are commonly written in their ___ form
unionized form
Amino acids’ internal salt form
zwitterion
a form of an amino acid with the presence of charged group (positive - amino group ; negative - carboxyl group)
zwitterion
form of an amino acid that results to net charge of 0
zwitterion
All amino acids have at least one stereocenter and are chiral except for
Glycine (Gly, G)
Vast majority of amino acids have this kind of configuration
L-configuration
2 types of configuration at the alpha carbon
L-configuration
D-configuration
Examples of D-configuration proteins
sugars and carbs
type of configuration that is prevalent in nature
L-configuration
Amino acids that are nonpolar (hydrophobic)
Alanine (Ala, A) Glycine (Gly, G) Valine (Val, V) Isoleucine (Ile, I) Leucine (Leu, L) Methionine (Met, M) Phenylalanine (Phe, F) Proline (Pro, P) Tryptophan (Trp, W)
Alanine (Ala , A) Side chain
Aliphatic (Hydrocarbon) side chain
Glycine (Gly, G) side chain
No stereocenter ; not chiral
Valine (Val, V) side chain
Aliphatic (hydrocarbon) side chain
Isoleucine (Ile, I) side chain
Aliphatic (hydrocarbon) side chain
isomer of isoleucine
Leucine (Leu, L) side chain
Aliphatic (hydrocarbon) side chain
Methionine (Met, M) side chain
Aliphatic (hydrocarbon) side chain
Additional Sulfur
Phenylalanine (Phe, F) side chain
Aromatic Ring side chain
Proline (Pro, P) side chain
Imino acid becaue of Secondary amino group
Tryptophan (Trp, W) side chain
Indole Ring (2 aromatic rings)
Amino acids with Polar and neutral / uncharged side chains
Asparagine (Asn, N) Glutamine (Gln, Q) Tyrosine (Tyr, T) Threonine (Thr, R) Serine (Ser, S) Cysteine (Cys, C)
Asparagine (Asn, N) side chain
aliphatic hydrocarbon and amide side chain
Glutamine (Gln, Q) side chain
aliphatic hydrocarbon and amide side chain
Tyrosine (Tyr, Y) side chain
aromatic ring and hydroxyl group side chain
Threonine (Thr, R)
Aliphatic hydrocarbon and hydroxyl group side chain
Serine (Ser, S) side chain
Aliphatic hydrocarbon and hydroxyl group side chain
Cysteine (Cys, C)
Aliphatic hydrocarbon and thiol / sulfihydryl group side chain)
Amino acids with acidic and charged side chains
Aspartic Acid (Asp, D) Glutamic acid (Glu, E)
Aspartic acid (asp, D) side chain
Aliphatic hydrocarbon and additional carboxyl group side chain
Glutamic acid (Glu, E) side chain
Aliphatic hydrocarbon and additional carboxyl group side chain
Amino acids with basic and charged side chains
Arginine (Arg, R)
Histidine (His, H)
Lysine (Lys, K)
Arginine (Arg, R) side chain
Aliphatic hydrocarbon and guanidino with additional amino group side chain
Histidine (His, H) side chain
Aliphatic hydrocarbon and aromatic ring and additional amino group
Lysine (Lys, K) side chain
Aliphatic hydrocarbon and additional amino group
Ability to rotate on its plane
Chirality of the Carbon
If we add a strong base such as NaOH to the solution and bring its pH to 14
a proton is transferred FROM the NH3+ making it a negative ion
If we add a strong acid such as HCl to bring the pH of the solution to 0.0
it denotes a proton TO the COO- making it a Positive Ion
The pH at which majority of the molecules of a compound in a solution has no net charge
Isoelectric point
Isoelectric point has how many charge
0
Formula of Isoelectric point (pI)
(Pk1+Pk2) / 2
Amino acid that is easily oxidized
Cyteine convertine -SH group to S-S disulfide
From Cysteine to Cystine
Amino acids that are used in protein of BRAIN TRANSMITTERS
Phenylalanine, Tryptophan, Tyrosine
Amino acids that undergo Hydroxylation (oxidation)
Proline - hydroxyproline
Lysine - hydroxylysine
Cysteine - cystine
Amino acids that undergo Iodination
Tyrosine - Thyroxine
AMIDE BOND between the alpha carboxyl group of an amino acid and amino group of another amino acid
Peptide bond
At physiological pH (7.4) the carboxyl group is ____, the amino group is ____ so an isolated amino acid would bear both a positive and negative charge
carboxyl group - Unprotonated
amino group - protonated
the different structure and function of amino acids are attributed by its
R-group
A short polymer of amino acids joined by peptide bonds; they are classified by the number of amino acids in the chain
peptide
a molecule containing two amino acids joined by a peptide bond
Dipeptide
a molecule containing three amino acids joined by peptide bonds
Tripeptide
a macromolecule containing many amino acids joined by peptide bonds
Polypeptide
a biological macromolecule containing at least 30-50 AMINO ACIDS joined by peptide bonds
Protein
individual amino acid units are referred to as
Residues
Formula of number of amino acid residues
number of amino acids - 1
A peptide bond is typically written as
carbonyl group bonded to an N-H group
There is about __% double bond character to the C-N bond of a peptide bond
40%
Peptide bond between two amino acid shows what kind of structure
PLANAR
the amino acid at the end of the chain having the free -COO- group
C-terminal amino acid
the amino acid at the end of the chain having the free -NH3+ group
N-terminal amino acid
At a pH above (more basic than) its pI it has a net charge of
NEGATIVE NET CHARGE
At a pH below (more acidic than) its pI it has a net charge of
POSITIVE NET CHARGE
Proteins are ____ in water at their isoelectric points
A. More soluble
B. Least soluble
B. Least soluble / Insoluble
Proteins at their isoelectric points can be __ from solution
precipitated meaning it can easily be separated since they are insoluble at this point
Amino acids are ___ and they can exist as ___
Stereoisomers ; Enantiomer