Chapter 2

Which of the following is a characteristic of double-stranded DNA?

2 nanometers in width, 10 base pairs per turn, and 0.34 nanometers per basepair

Covalent Bond

bond formed when electrons are shared between two atoms. Occurs when both atoms require electrons.

In contrast to other fatty acids, essential fatty acids

cannot be synthesized by the organism and are necessary for survival

Molecules that contain the element ___ are considered organic molecules

carbon

____ is _____ and most organisms lack the necessary enzyme to hydrolize the beta D glucose monomers. It is used primarily for ______ in plants

cellulose, unbranched, structural support

The ___ of a nucleotide determines where it is a component of dna or a component of RNA

five carbon sugar

Where are most plasma free fatty acids obtained from?

hydrolisis of stored fat

Trans fats have a higher melting point than natural unsaturated fats and a lower melting point than natural saturated fats

true

Unsaturated fats have kinks in the hydrogen-carbon chain and therefore the molecules do not lay flat

true

liquid at room temp, oil,found in plants and plant products,double bonds within carbon backbone, transfat are a synthetic form that has a higher melting point

unsaturated fatty acid

Nonpolar Covalent Bond

where two atoms share a pair of electrons with each other.

The charged ends of a water molecule allow it to surround a solute in solution.

Solvent

___ is a polysaccharide that is found primarily in plant cells as a form of energy storage. It is ___ ___ , and as a result is not very soluble in water.

Starch, moderately branched

Polar covalent bond is created when

atoms within the bond do not have the same pull on the shared electron, and as a result the electron spends more time around one atom relative to the other atom within the bond.

The bond between a carbon and hydrogen atom is a polar bond

False

The bonds between water molecules are stable.

False

Saturated fats have one or more double bonds along the carbon backbone

false

Trans fats are synthetic saturated fats

false

Unsaturated fats are found primarily in animals and animal products

false

lipid

fatty acid

Ionic Bond

A chemical bond formed between two ions with opposite charges.

Dehydration Synthesis

A chemical reaction that builds up molecules by losing water molecules.

Hydrolysis

A molecule of water is added to break the covalent bond between the monomers

1. HCl -> H+ + Cl- 2. H2CO3 -> H+ + HCO3-

Acid

___ are the building blocks of protein. They are made up of a center carbon atom bound positively to a charged ___ group and a negatively charged ___ group and a side chain.

Amino acids, amino group, carboxyl group

Polyatomic Ions

An ion made of more than one atom. All are anions except one.

Polar Covalent Bond

Atoms with different electronegativity share electrons unequally

1. NaOH -> Na+ + OH- 2. NH3 + H2O -> NH4 + OH-

Base

Carbon Skeleton Formation

Carbon can bond in straight chains, branched chians, or rings

The high specific heat of water means that we only lose a small amount of heat when the sweat on our skin evaporates

False

Lipids

Contain C, H, O. Are fats and oils. Are NON-POLAR

Carbohydrates

Contain Carbon, hydrogen, and oxygen. Their major funtion is to supply source of cellular food

Strong chemical bonds due to the sharing of electrons. Bonds between hydrogen and oxygen atoms within a molecule.

Covalent bonds

double stranded, housed within the nucleus of an animal cell, AT GC

DNA

Water is formed when two molecules come together to form a large molecule.

Dehydration reaction

Octet Rule

Elements tend to lose, gain, or share elctrons to obtain complete outer shells with eight electrons

A carbon atom has six electrons in its outermost shell

False

A hydrogen atom of one water molecular binds via a hydrogen bond to a hydrogen atom of another water molecule

False

Bonds between water molecules are stronger than the bonds between the atoms within a water molecule

False

Ten to twenty percent of the body weight in humans is from water.

False

Organic Molecules

Generally contain carbon and made of living things.

___ is a storage of polysaccharides commonly found in the cells of animals

Glycogen

____ is a polysaccharide primarily stored in muscle tissue. It is ___ _____ allowing hydroxyl side groups to be readily exposed to water in the surrounding tissue, for easy hydrolysis

Glycogen, highly branched

Dehydration synthesis reaction C6H12O6+C6H12O6 --->

H2O+C12H22O11

Anions

Have a negative charge, some atoms gain e-

Cations

Have a positive charge, some atoms lose e-

The addition of water can break apart molecules into two smaller molecules.

Hydrolysis

Electrons are transferred between two atoms creating positively and negatively charged atoms, which then attract to each other. Na+ + Cl- --> NaCl

Ionic bonds

Organic Compounds

Lipids, Carbohydrates, Proteins, Nucleic Acids

Due to hydrogen bonding, water tends to adhere to surfaces, such as the lining of the digestive tract.

Lubricant

single stranded, AU GC, ribose sugar within the backbone

RNA

plays a role in protein synthesis

RNA polymerase

The fluid nature of water is due to hydrogen bonds continually breaking and reforming.

True

The polar covalent bonds between hydrogen and oxygen atoms within a water molecule create slight positively and negatively charged ends to the molecule.

True

Water bathes organs in fluid, which provides protection and support

True

Water is the universal solvent, transporting dissolved substance in bodily fluids

True

Inorganic Molecules

Water, Salts, Acids, Bases

Isotope

a chemical element is an atom that has a different number of neutrons

Functional groups help define the properties of macromolecules. The _____ functional group(s) is/are found within amino acids, while carbohydrates contain the _____ functional group(s).

amino & carboxyl // hydroxyl

Monomer of a protein

amino acid

The monomers of proteins are _____ and these are linked bhy polar covalent bonds commonly referred to as ____

amino acids, polypeptide

Phospholipids ae amphipathic, which means they

are composed of a hydrophilic portion and a hydrophillic portion

Certain types of fats used in baking are called shortenings. They are solid at room temperature. Shortenings are often made from vegetable oils by a process called hydrogenation. What do you think happens to the structure of an oil when it is hydrogenated?

changes them to a saturated fat, causing them to be solid at room temps

The _____ of the water molecules, resulting from ____ bonds between water molecules, causes a movement of water through the plants vessels as it moves up from the roots.

cohesion, hydrogen

If two proteins have the same complement of amino acids, what would increase the likelihood that the two proteins would behave differently, e.g., have different functions?

different sequence of the amino acids within the molecules

sucrose, maltose, lactose, c12h22o11

disaccharide

As water ____ from the pores in the leaves,more water is pulled up from below resulting in a constant supply of water moving up through the vessels of a plant

evaportates

Bonds between carbon and other atoms are relatively unstable and readily dissociate, resulting in the formation of new molecules.

false

Carbon is a relatively large atom allowing it to bind to more atoms than smaller atoms would, thereby making it more versatile

false

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

hydrophobic portions

Peptide bond (amide bond)

is a covalent chemical bond formed between two amino acid molecules.

____ are molecules that hae the same molecular composition but differ to structure and or bonding association

isomers

Carbohydrate

monosacharrides

Glucose, fructose, c6h12o6

monosacharrides

A person who sprints for 45 seconds obtains most of their energy from

muscle glycogen

plays a role in muscle contraction / movement

myosin

Nucleic acid

nucleotide

What type of bonds link individual amino acids together

peptide

The correct structure of DNA components can be presented as

phosphate-sugar-base

The unequal sharing of electrons between the oxygen and the hydrogen atoms within a water molecule makes water a ____ molecule

polar molecule

When water and oil are added to a test tube, the two liquids form two separate layers (think of oil and vinegar in a bottle of salad dressing). If a solution of phospholipids were added to a mixture of water and oil, where would the phospholipids dissolve?

polar regions would dissolve in the water and the nonpolar regions would dissolve in the oil

____ formed by ______ reactions link amino acids together forming a linear chain.

polypeptides, dehydration

cellulose, starch, glycogen

polysaccharide

The ____ structure of a protein is the sequence of an amino acids that are attached together by a ____ bond.

primary structure, peptide

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

protein is denatured

DNA _______. RNA, on the other hand, ________.

provides the instructions for the specific sequence of amino acids used to build a protein // functions to convert a nucleotide sequence into an amino acid sequence

no double bonds within carbon backbone, solid at room temperature, comes from animal and animal products

saturated fatty acid

The helix that forms in a protein chain as a result of hydrogen bonds and other weak forces is an example of

secondary structure

In the ____ structure of a protein the polypeptide is folded through the mechanisms of amino acids rotating around bonds folding into an a helix or a b pleated sheet structure and stablized by a ___ bond.

secondary, hydrogen

As a result of electron configuration of a water molecule, water is a great _______ because water can break up and surround a ______, as long as it is not ______, dissolving it into solution

solvent, solute, nonpolar.

In the ___ structure of a protein the amino acid side chains of the folded polypeptide interact, forming a commplex _____ shape

tertiary, 3d (three deminsional)

Hydrogen Bonds

the attractive force between the hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule

What type of reaction is the reverse of the ones shown here, in which a disaccharide is broken down into two monosaccharides?

the reverse of a dehydration reaction is called a hydrolysis reaction.

facilitates movement of molecules across plasma membranes

transporters

A carbon atom can form up to four covalent bonds

true

Oxygen and nitrogen have a stronger electronegativity than carbon (e.g., a strong pull on a shared electron

true

Saturated fats are solid at room temperature

true

Saturated fats have a higher melting point than unsaturated fats

true

The carbon backbone of a molecule comes in a variety of shapes: linear, ring-like, or highly branched

true

The carbon backbone of a molecule is made up of a string of carbon atoms held together with either single or double bonds

true