Bio152 Ch. 3

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in the stable form of protein, what is generally oriented to the interior of the protein molecule?

hydrophobic portions

when phospholipid molecules are mixed with water, they can spontaneously organize into a bilayer with the "heads" located __________ of the bilayer.

on the surface

when an egg is fried, what happens to the protein in the egg?

the protein is denatured

the fatty acid of a triglyceride need not be identical, and often they are very different from one another

true

when proteins are denatured, which type of bond is not disturbed?

covalent bonds

Ala-Gly-Try-Lys-Met-Trp-Phe

Primary structure

The sequence of amino acids in the polypeptide chains

Primary structure

In a phospholipid molecule, ________ usually binds to a charged organic molecule, such as choline or the amino acid serine.

a phosphate group

polar soluble, can act as a weak base and accept a proton, found in proteins and nucleic acids

amino group

lipid bilayers form the basic framework of _____________.

biological membranes

polar, soluble, protons can dissociate from this group and it has acidic properties

carboxyl group

a molecule of glycogen is formed by linking glucose molecules through this process.

dehydration synthesis

monomers are linked together through this process

dehydration synthesis

this process removes water to link two or more amino acids

dehydration synthesis

the change to the color and consistency of an egg during cooking is an example of this process.

denaturation

this process does not involve breaking peptide bonds, bit it does involve unfolding protein structure

denaturation

using acids to cook raw fish is an example of this process

denaturation

a protein that has many hydrophobic R-groups pointing to the outside of the protein would be found?

embedded within the membrane

a fatty acids consists of a hydrocarbon chain joined to a hydroxyl group

false

a saturated fatty acid has the maximum number oxygen atoms bonded to its hydrocarbon chain

false

a tricylglycerol is composed of 3 glycerol molecules joined to a fatty acid

false

denatured proteins are usually biologically active

false

fats containing unsaturated fatty acids have high melting points because their fatty acid chains bend at the double bonds, preventing them from packing closely together

false

glycerol is a three-carbon alcohol, in which each carbon bears a carboxyl group

false

if a proteins environment is altered, the protein may change its shape or even unfold completely, a process called dissociation.

false

proteins have a narrow range of conditions in which they fold, outside that range, proteins tend to renature

false

the final 3-D shape of a protein is determined entirely by its primary structure

false

when normal environmental conditions are reestablished after protein denaturation, almost all proteins can spontaneously refold back into their natural shape.

false

In a phospholipid molecule, _____ binds to two fatty acids

glycerol

breaking DNA into nucleotides involves this process

hydrolysis

the addition of water to break proteins into amino acids is an example of the process.

hydrolysis

the separation of polymers into smaller units makes use of this process.

hydrolysis

in a phospholipid molecule, the "head" is ________.

hydrophilic

in a phospholipid molecule, the fatty acid "tails" are______.

hydrophobic

polar, soluble, forms H bonds, forms alcohol

hydroxyl group

when phospholipid molecule are mixed with water, they can spontaneously organize into bilayer with the "tails" located _________ of the bilayer

in the center

nonpolar, hydrophobic, found in hydrocarbon chains

methyl group

what type of bonds link individual amino acids together?

peptide bonds

polar, soluble, found in nucleic acids, can be acidic if it loses protons

phosphate group

what levels of protein structure would be affected if all hydrogen bonding interactions were prevented.

primary secondary

only found in proteins composed of more than one polypeptide chain

quaternary

refers to the way several different polypeptide chains fit together to form the final protein

quaternary structure

Alpha- helix and beta-pleated sheets

secondary structure

repeated pattern of coiling or folding within a polypeptide chain

secondary structure

results from hydrogen bonds between polar groups in the polypeptide backbone

secondary structure

results from the bending and folding of a polypeptide chain that occurs due to a variety of interactions between the amino acid side chains

tertiary structure

the overall 3-D shape of polypeptide or protein

tertiary structure

a hydro carbon chains of fatty acids vary in length as well as in the number and location of double bonds between the carbon atoms

true

cells use chaperones both to accomplish the original folding of some proteins and to restore the structure of incorrectly folded ones

true

during a process called dissociation, the polypeptides of a protein with quaternary structure separate and unfold, losing their individual tertiary structure

true

fatty acids with one double bond in their hydrocarbon chain are called monounsaturated, while those with more than one double bond are called polyunsaturated

true

if the 3-D structure of a protein depends only on its primary structure and the surrounding environment conditions, then when the protein is denatured and subsequently returned to its native conditions it will spontaneously refold back to its native structure.

true

most plant fats are partially hydrogenated industrially, this can produce trans fats which have been linked to elevated levels of low-density lipoprotein (LDL) "bad cholesterol" and lowered levels of high-density lipoprotein (HDL) "good cholesterol"

true

proteins can denature when the pH, temperature, or ionic concentration of surrounding solution changes

true

some diseases may occur because a protein with the correct amino acid sequence fails to correctly fold into its final functional form

true

some proteins require other proteins called chaperones in order to correctly fold into their normal 3-D shape

true

when forming a semi-solid gel such as gelatin, which molecule does the process of protein coagulation entrap?

water molecules


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