Unit 2: Proteins Flashcards
Proteins are one of the most ___, ___ in living systems
abundant, organic molecules
Proteins are the main molecules that carry out
the functions of the cell.
The major reason that proteins are so varied in their function is due to
their ability to bind other molecules.
Ligand
A molecule that a protein binds
Protein Structure
Amino acid polymers arranged in a linear sequence, with each protein having a unique function and structure.
Binding Site
The place on a protein where binding occurs; determined by the protein’s shape.
Protein provides (8)
Proteins may be; structural, contractile,
protect, defend,
transport, store,
communicate, regulate,
toxins, enzymes.
Various proteins can bind other proteins, such as (6)
DNA, RNA, lipids, carbohydrates, ions, or small molecules.
Proteins are synthesized by _______, which attach ______ together to form a _____, which folds into its three-dimensional shape.
ribosomes, amino acid polymers, polypeptide
Protein Folding is critical for__ and is aided by __
Structure & function; chaperonins
Chaperonins
Assist in protein folding, prevent aggregation, and disassociate post-folding.
Denaturation is an alteration in protein___ and is caused by changes in___(3).
shape (not sequence). temp, pH, or chemicals.
Reversible Denaturation
Proteins can refold and regain function after denaturation.
Irreversible Denaturation
Permanent loss of protein function due to denaturation.
The shape of a protein is crucial for its ___ and is determined by its ___(4) levels of structure.
function. primary, secondary, tertiary, and quaternary.
Enzyme
A protein that acts as a biological catalyst, facilitating specific chemical reactions.
Active Site
The specific region on an enzyme where the substrate binds and the chemical reaction occurs.
Primary Structure
The unique sequence of amino acids in a protein’s polypeptide chain.
The gene encoding the protein ultimately determines
the unique sequence for every protein.
Secondary Structure
The local folding patterns of the polypeptide chain, often forming α-helices or β-pleated sheets.
Tertiary Structure is a __ structure of a protein, influenced by interactions __.
three-dimensional; among R groups
When a protein loses its three-dimensional shape, it
may no longer be functional.
Quaternary Structure
The structure that results from the interaction of multiple protein subunits.
Hydrogen bonds are __ bonds formed between __, crucial for maintaining protein __ structures.
Weak chemical, hydrogen atoms and other atoms, secondary and tertiary
Disulfide bond is a __ bonds formed between two__ & two__, contributing to protein__.
Covalent, cysteine amino acids, sulfhydryl groups, folding and stability
Insulin is a __ protein that forms a __ structure through __ (2) bonds, crucial for regulating blood sugar levels.
globular, quaternary, hydrogen and disulfide
Amino acids are protein __
monomers
What is the fundamental structure of an amino acid?
It includes a central carbon atom bonded to an amino group, a carboxyl group, a hydrogen atom, and an R group.
What is an R group in an amino acid?
Atom or group of atoms bonded to the central carbon atom, determining the amino acid’s chemical nature.
The R group determines whether an amino acid is __(4)?
It determines whether the amino acid is acidic, basic, polar, or nonpolar.
The sequence and the number of amino acids ultimately determine the protein’s
shape, size, and function.
A peptide bond is a__ bond formed between__ through a dehydration reaction, involving the combination of one amino acid’s__ group with another amino acid’s__ group, releasing a water molecule.
Covalent, amino acids, carboxyl, amino
Polypeptide
A polymer of amino acids.
How are amino acids linked in a polypeptide?
By peptide bonds.
What terminal is the free amino group located on a polypeptide chain?
At the N terminal end.
What terminal is the free carboxyl group located in on a polypeptide chain?
At the C terminal end.
Protein is made up of a __ that have combined together, often with__ prosthetic groups, possessing a distinct shape and unique function.
Polypeptide(s), non-peptide,
Essential amino acids are__ that the human body cannot __ and must be obtained from the__ to build proteins.
amino acids; produce; diet
The “alpha carbon” is found where?
it is the carbon adjacent to the hydroxyl on a carbonyl
Ribosomes are composed of what types of molecules?
proteins and RNA
An alpha helix is an example of a ____ structure, and is held together by ___.
secondary, hydrogen bond
What are some causes of disease
Infection, genetic (mutations, inherit genes) and environmental factors (diet, exposure to chemicals)
