Cell Bio Quiz 2

a van der Waals force.

A weak attractive force between two molecules with transitory dipoles that are very close to one another and oriented in an appropriate manner is called

can be caused by detergents, organic solvents, heat, certain chemical compounds, or radiation.

Denaturation of a protein:

Isoforms

Different versions of a protein, which are adapted to function in different tissues or at different stages of development are called:

Domains.

Distinct regions of a protein that fold independently of one another and often function in a semi-independent manner are called:

Cysteine.

Disulfide bridges can form between two residues of:

deep in a protein's core where water is excluded

In a cell, where are strong ionic bonds most likely to be found?

the carboxyl group of one amino acid joins with the amino group of the adjacent amino acid, and water is lost.

In a polypeptide, when peptide bonds are formed between adjacent amino acids:

heat shock proteins.

Molecular chaperones were originally referred to as:

may prevent growing proteins from making random, nonselective interactions with other proteins in various cellular compartments.

Molecular chaperones:

Amphipathic.

Molecules having both hydrophobic and hydrophilic regions are said to be:

hydrophilic; hydrophobic

Polar molecules are __________. nonpolar molecules are __________. (Hyrdoph---)

requires use of a computer to compare fingerprints of extracted proteins to those of known proteins. is furthered by mass spectrometry that provides a pattern characteristic of individual proteins. is based on knowledge of the genome of a cell. can reveal changes in protein composition within a cell over time.

Study of the proteome of a cell:

carbohydrates, lipids, proteins, and nucleic acids

The four major biological molecules are:

20,000 to 22,000

The human genome contains how many genes?

Glycogen.

The liver stores energy in the form of a polysaccharide called:

the function of a protein.

The study of proteins using siRNAs is MOST useful in determining:

noncovalent interactions between side chains of amino acids.

The tertiary structure of a protein is stabilized by:

the diverse side chains on the different amino acids.

The variability among polypeptides is primarily due to:

transient asymmetric electron density shifts Where are hydrophobic interactions most likely to occur? the core of a water-soluble protein in contact with water molecules on the surface of a water-soluble protein between two charged molecules between two ions the core of a water-soluble protein

Van der Waals forces are the result of - ionic attractions - aggregation to exclude water from hydrophobic molecular faces - transient asymmetric electron density shifts - hydrophilic molecular attractions to one another

form hydrogen bonds with up to four other water molecules.

Water has extraordinary properties to support life such as the capacity to

high probability of bonding with nonpolar molecules

Water's life-supporting properties include all of the following EXCEPT: - ability to dissociate into OH- and H+ units within the cell - high probability of bonding with nonpolar molecules - high boiling point compatible with temperate extremes of summer allowing energy to be released through sweat - protection from cold and damaging radiation by providing the matrix around which the cellular framework is constructed.

Hydrogen bonds.

Weak attractions between adjacent water molecules are which type of bond? Hydrogen, polar covalent, ionic, hydrophobic, van der Waals

Non-polar regions of the protein are repelled by water, driving them to the interior of the molecule.

What is the hydrophobic effect? (Water is sometimes called the 21st amino acid because of its importance in defining protein structure. The basis for this is the so-called hydrophobic effect.)

hydrogen bonds

Which interaction is most important in enhancing the solubility of macromolecules in water?

The water molecule readily forms hydrophobic interactions.

Which of the following characteristics does NOT apply to water? The water molecule is asymmetric. The water molecule readily forms hydrophobic interactions. The covalent bonds in water are strongly polarized. All three atoms in the water molecule readily form hydrogen bonds. Water is an excellent solvent.

B.

Which of the groups participates exclusively in hydrophilic interactions?

E.

Which of the groups participates exclusively in hydrophobic interactions?

Proteins with identical sequences of amino acids must also have identical folding patterns, even when interacting with different substances.

Which one of the following statements is FALSE? - Proteins are biochemical adaptations that are subject to evolutionary change. - Proteins with identical sequences of amino acids must also have identical folding patterns, even when interacting with different substances. - Small changes in amino acid sequence may have dramatic effects on protein shape. - The greater the evolutionary distance between two organisms, the greater the difference in the amino acid sequences of their proteins. - Genes that encode members of a protein family are thought to have arisen from a single ancestral gene.