chapter 4 cell and moleculer

Provides the cell with shape and structure (tubulin and
actin

Structural Protein

Catalyze covalent bond breakage or formation (pepsin)

Enzymes

Carries other molecules or ions (hemoglobin - oxygen)

Transport Protein

Generates movement in cells and tissues (Myosin)

Motor Protein

Stores small molecules or ions (ferritin - iron in liver)

Storage Protein

Carries signals from cell to cell (insulin - glucose levels

Signal Protein

Detects signals and transmits them to the cell’s Gene Regulatory Proteinresponse machinery (insulin receptor)

Receptor Protein

Binds to DNA to switch genes on or off (transcriptional factors - lactose repressor)

Gene Regulatory Protein

peptide bonds

amino acids are linked together by

polypeptide chain

A Protein is made of amino acids linked together into a

non-covalent bonds or interactions

what helps proteins fold

When a hydrogen atom is “sandwiched” between electron-attracting atoms (oxygen or nitrogen).

hydrogen bonds:

attractions between charged groups

noncovalent bond electrostatic attractions:

attractions between two atoms at very short distances.

van der Waals attractions:

nonpolar molecules or parts of molecules avoid water and cluster together.

Hydrophobic interaction:

Hydrophobic forces

What help proteins fold into compact conformations

hydrogen bonds

What within a protein molecules help stabilize its folded shape

denatured proteins

what can recover their natural shapes to maintain a conformation of lowest enrgy

prion diseases

what are caused by rare proteins whose misfolding is infectious

chaperone proteins

What can guide the folding of a newly synthesized polypeptide chain

chaperone proteins

what acts as an isolation chamber that help a polypeptide fold

alpha helix

What is a common folding pattern?

The N-H of every ____ is ____ to the C = O of a neighboring peptide bond located four amino acids away in the same chain

linear amino acid sequence of a protein

What is the primary level of protein orginization?

repeating folding patterns

What is the secondary level of protein orginization?

fully folded form of a single polypeptide= conformation

What is the tertiary level of protein orginization?

a fully folded 3d form of a protein, the shapes it end up in

conformation

2 or more polypeptide subunits interacting and binfing with one another

What is the quaternary level of protein organization?

chain of amino acids

polypeptide

intertwined alpha helices

what forms a coiled coin?

beta sheet

What is a common folding patter of proteins

hydrogen-bonding between peptide bonds in different strands

The individuals strand in the beta sheet are held toget by what?

parallel and antiparallel

What are the two varieties that beta sheets come in?

functional domains

Many proteins are composed of separate what?

amyloid structures

When proteins fold, what can they sometimes form?

serine proteases

what comprise a family of proteolytic enzymes?

multiple

How many copies can protein molecules contain of a single protein subunit?

complex structures

proteins can assemble into ______?

dimer

a protein complex made of 2 polypeptide subunits

actin filament

what is composed of a identical protein subunit?

filament,tube or spherical shell

what can a single protein subunit pack to form?

a triple helix formed by three protein chains that wrap around each other

what is a collagen formed by?

Disulfide bonds

what help stabilize a favored protein conformation?

scaffold proteins

what can concentrate interacting proteins in the cell?

scaffolds

many proteins are brought together by what?