Proteins (PPT based) Flashcards
are naturally occurring, unbranched polymer in which the monomer units are amino acids
PROTEINS
Is a peptide in which at least 40 amino acid residues are present.
PROTEINS
Examples of PROTEINS:
messengers
HORMONES
Examples of PROTEINS:
speed up reactions
ENZYMES
Examples of PROTEINS:
“antinnae”
CELL RECEPTORS
Examples of PROTEINS:
fight foreign invaders
ANTIBODIES
Examples of PROTEINS:
allowing specific molecules to enter or leave a cell
MEMBRANE CHANNELS
the building block of proteins
AMINO ACID
is an amino acid in which the amino group and the carboxyl group are attached to the carbon atom
a-amino acid
has a structural feature not found in any other standard amino acid.
Proline
GIV-LAP-MWF
NON POLAR AMINO ACID
CNS-TQY
POLAR NEUTRAL
HKR
POLAR BASIC
DE
POLAR ACIDIC
is a standard amino acid needed for protein synthesis that must be obtained from dietary sources because the human body cannot synthesize it in adequate amounts from other substances.
ESSENTIAL AMINO ACIDS
Synthesized by the body
NON-ESSENTIAL AMINO ACIDS
occurs in people who have a severe protein deficiency. Children who develop this disorder are often older than children who develop marasmus.
KWASHIORKOR
symptoms of this disorder includes:
Inability to grow or gain weight, Edema or swelling of the hands and feet, Stomach bulging
KWASHIORKOR
occurs more often in young children and babies. It leads to dehydration and weight loss. Starvation is a form of this disorder
MARASMUS
symptoms of this disorder includes:
Weight loss, Dehydration, Stomach shrinkage
MARASMUS
Removes toxic substances released from breakdown of muscle protein during intensive exercise
Ala
antioxidant (free radical scavenger), and has synergetic effect when taken with other antioxidants
Cys
Promotes healthy brain function. It is also necessary for the synthesis of RNA and DNA molecules.
Gln
Component of skin and is beneficial for wound healing. It acts as neurotransmitter
Gly
Important for the synthesis of red and white blood cells. It is a precursor for histamine which is good for sexual arousal. Improve blood flow
His
It helps promote equilibrium in the central nervous system—aids in balancing state of emotion.
Thr
Uncommon amino acids derived from Posttranslational Modification:
found in the cell walls of many bacteria
D-glutamic acid
Uncommon amino acids derived from Posttranslational Modification:
found in earthworms
D-serine
Uncommon amino acids derived from Posttranslational Modification:
one of the neurotransmitters in the brain
GABA
Uncommon amino acids derived from Posttranslational Modification:
a constituent of the vitamin pantothenic acid
β-alanine
Glucogenic, Ketogenic, or Both:
glycine, alanine, serine, aspartic acid, asparagine, glutamic acid, glutamine, proline, valine, methionine, cysteine, histidine and arginine
GLUCOGENIC
Glucogenic, Ketogenic, or Both:
tryptophan, phenylalanine, tyrosine, isoleucine and threonine
BOTH
Glucogenic, Ketogenic, or Both:
lysine and leucine
KETOGENIC
means double ion Is a molecule that has a positive charge on one atom and a negative charge on another atom but which has no net charge
Zwitterion
NH3+ of the zwitterion loses a proton and negatively charged species is formed
Basic solution
the zwitterion accepts a proton (H+) to form a positively charged ion
Acidic solution
the pH at which an amino acid exists primarily in its zwitterion form
ISOELECTRIC POINT
At the ________, almost all amino acid molecules in a solution (more than 99%) are present in their zwitterion form
isoelectric point
a covalent bond (amide bond) between the carboxyl group of one amino acid and the amino group of another amino acid.
Peptide bond
is an unbranched chain of amino acids, each joined to the next by a peptide bond.
Peptide
TYPES OF PEPTIDE:
a compound containing two amino acids
dipeptide
TYPES OF PEPTIDE:
three amino acids joined together in a chain
Tripeptide
TYPES OF PEPTIDE:
refer to peptides with 10 to 20 amino acid residues.
Oligopeptide
TYPES OF PEPTIDE:
long unbranched chain of amino acids, each joined to the next by a peptide bond.
Polypeptide
Hormones both produced by the pituitary gland:
- Oxytocin
2.Vasopressin (ADH)
regulates uterine contraction and lactation, plays a role in stimulating the flow of milk in a nursing mother.
Oxytocin
regulates the excretion of water by the kidneys
Vasopressin (ADH)
Enhances reabsorption of free water also affects blood pressure.
Vasopressin (ADH)
Neurotransmitter: pain killers
(pentapeptide): neurotransmitters or neuromodulators at many locations in the brain and spinal cord and are involved with pain perception, movement, mood, behavior, and neuroendocrine regulation; they are also found in nerve plexuses and exocrine glands of the gastrointestinal tract
Enkephalins
Antioxidant: regulator of oxidation-reduction reaction
Glutathione
Antioxidants: protecting cellular contents from oxidizing agents such as peroxides and superoxides (highly reactive forms of oxygen often generated within the cell in response to bacterial invasion) with unusual features.
Glutathione
Bonding in proteins:
the strongest bond
Peptide bond
Bonding in proteins:
is a covalent bond between two sulfur. Results from the oxidation of the –SH (sulfhydryl) groups of two cysteine molecules to form “cystine”
Disulfide bond
Bonding in proteins:
result from the attraction of electronegative atoms in the protein molecule. Weaker than the peptide and disulfide bonds.
Hydrogen Bond
formed between groups which are positively and negatively charge
Ionic bond or salt bridges
formed by amino acids like leucine, valine, phenylalanine, tryptophan, and proline which adhere each other forming a “micelle” and which do not mix well with water
Hydrophobic bond
is a protein in which only one peptide chain is present.
monomeric protein
is a protein in which more than one peptide chain is present.
multimeric protein
The peptide chains present in multimeric proteins are called _________.
protein subunits
is a protein in which only amino acid residues are present.
Simple protein
Based on chemical composition:
Properties:
a. Soluble in water and dilute neutral salt solution
b. Coagulated by heat and precipitated by full saturation with (NH4)2SO4 but not w/ NaCl except with the presence of acid.
Albumins
Based on chemical composition:
Properties:
a. Soluble in neutral dilute salt solutions but not in water (Neutral salts refers refer to salts of strong acids and bases as NaCl, MgSO4 and (NH4)2SO4.)
b. Coagulated by heat and can be precipitated from their solutions by half saturation with (NH4)2SO4 and complete saturation with NaCl.
Globulins
Based on chemical composition:
Properties:
Soluble in dilute acids and alkalies but insoluble in neutral solvents
Glutelins
Based on chemical composition:
Properties:
a. Insoluble in ordinary solvent (water, dilute salt solutions, dilute acid and alkalies) but soluble in 70% alcohol at about neutral point. b. Not coagulable by heat.
Prolamines
Based on chemical composition:
Properties:
a. Soluble in water, dilute acids and alkalies but not in ammonia.
b. Not readily coagulated by heat
c. Strongly basic and occur in the tissues in the form of salt combinations with acid substances like the heme of the hemoglobin
Histones
Based on chemical composition:
Properties:
a. Contain smaller number of amino acids
b. Soluble in water and dilute acids and alkalies
c. Not coagulated by heat
Protamines
Based on chemical composition:
Properties:
Insoluble in water and neutral solvents
Scleroproteins (Albuminoids)
is a protein that has one or more non-amino acid entities present in its structure in addition to one or more peptide chains
Conjugated protein
is a non-amino acid group present in a conjugated protein. These non-amino acid components, which may be organic or inorganic
prosthetic group
These include substances formed from simple conjugated proteins.
Derived proteins
proteins which have undergone slight intramolecular rearrangement through the hydrolytic action of certain physical and chemical agents
Primary Protein derivatives
synonymous w/ denatured proteins
Primary Protein derivatives
Product of more extensive hydrolysis
Secondary Protein derivatives
Mixtures of fragments of original proteins varying in composition and size
Secondary Protein derivatives
Exhibit certain common properties such as solubility in water and non-coagulability by heat.
Secondary Protein derivatives
Secondary Protein derivatives:
Soluble in water, precipitated by conc.HNO3 and by half saturation with (NH4)2SO4 or ZnSO4. Not coagulated by heat
Primary proteoses
Secondary Protein derivatives:
Precipitated only by complete saturation with (NH4)2SO4 but not with picric acid and HNO3
Secondary proteoses
Sequence of amino acids in a protein – that is, the order in which the amino acids are connected to each other
PRIMARY STRUCTURE
Also involves the order of attachment of the amino acids to each other through covalent peptide bonds
PRIMARY STRUCTURE
Is the arrangement in space adopted by the backbone portion of a protein
SECONDARY STRUCTURE
Is a result of hydrogen bonding between carbonyl oxygen atom of a peptide linkage and the hydrogen atom of an amino group of another peptide linkage farther along the backbone.
SECONDARY STRUCTURE
Common types of secondary structures:
- Alpha helix
- Beta pleated sheet
is a protein secondary structure in which a single protein chain adopts a shape that resembles a coiled spring (helix), with the coil configuration maintained by hydrogen bonds.
ALPHA HELIX
What bond forms between oxygen and hydrogen peptide linkage atoms
Hydrogen bonds
The overall three-dimensional shape of a protein that results from the interactions between amino acids side chains (R groups) that are widely separated from each other within a peptide chain.
TERTIARY
Four types of stabilizing interactions contribute to the tertiary structure of a protein:
- covalent disulfide bonds
- electrostatic attractions (salt bridges)
- Hydrogen bonds
- hydrophobic attractions
Is the organization among the various peptide chains in a multimeric protein
QUATERNARY
The three-dimensional shape of a protein consisting of two or more independent peptide chains, which results from noncovalent interactions between R groups
QUATERNARY
This is also when the protein associates with non-proteic groups. For example, carbohydrates can be added to form a glycoprotein
QUATERNARY
Protein whose molecules have an elongated shape with one dimension much longer than the others.
Fibrous
Tend to have simple, regular and linear structures.
Fibrous
Largely insoluble in ordinary aqueous media, Molecular weights are high, Functions is for structural and support
Fibrous
found in wool, feathers, hooves, silk, and fingernails
Keratins
found in tendons, bone, and other connective tissue
Collagens
found in blood vessels and ligaments
Elastins
found in muscle tissue
Myosins
found in blood clots
Fibrin
Protein whose molecules have peptide chains that are folded into spherical or globular shapes.
Globular
The folding in such that most of amino acids with hydrophobic side chains (nonpolar R groups) are in the interior of the molecules and most of the hydrophilic side chains (polar) are on the outside of the molecule.
Globular
Properties:
● Soluble in aqueous media
● Have been crystallized and have definite molecular weights
● Can be denatured
Globular
regulatory hormone for controlling glucose metabolism
Insulin
involved in oxygen storage in muscles
Myoglobin
involved in oxygen, transport in blood
Hemoglobin
involved in iron transport in blood
Transferrin
involved in immune system responses
Immunoglobulins
FIBROUS OR GLOBULAR:
water-insoluble
FIBROUS
FIBROUS OR GLOBULAR:
Water-soluble
GLOBULAR
FIBROUS OR GLOBULAR:
usually have a single type of secondary structure
FIBROUS
FIBROUS OR GLOBULAR:
several types of secondary structure.
GLOBULAR
FIBROUS OR GLOBULAR:
generally have structural functions that provide support and external protection
FIBROUS
FIBROUS OR GLOBULAR:
involved in metabolic chemistry, performing functions such as catalysis, transport, and regulation.
GLOBULAR
FIBROUS OR GLOBULAR:
Lesser in kind of proteins
FIBROUS
FIBROUS OR GLOBULAR:
Greater in kind of proteins
GLOBULAR
FIBROUS OR GLOBULAR:
Most abundant in the human body
FIBROUS
FIBROUS OR GLOBULAR:
Less abundant in the human body
GLOBULAR
FIBROUS OR GLOBULAR:
Greater mass composition
FIBROUS
FIBROUS OR GLOBULAR:
Lesser mass composition
GLOBULAR
is a protein that is found associated with a membrane system of a cell.
MEMBRANEOUS
Soluble in aqueous media, Have been crystallized and have definite molecular weights, Can be denatured
MEMBRANEOUS