Bio ch 2

which of the following describes facilitated diffusion

it requires the assistance of proteins it requires a concentration gradient

what are lipids

lipids are hydrophobic molecules composed primarily of hydrogen and carbone

arrange the following states of water in order from MOST dense to LEAST dense

liquid solid gas

the cells of all living things are composed of ____; very large molecules that contain thousands and in some cases even billions of atoms

macromolecules

a dalton is a unit of

mass

which of the following are methods of passive transport

osmosis transport of water by aquaporins

electrons in the same energy level

always have the same potential energy

by applying chemical stains to cells, we can improve which of the following between different cellular components

contrast

which of the following are mechanisms of bulk transport

exocytosis endocytosis

a ____ _____ consists of a long chain hydrocarbon with a carboxyl group attached to one end

fatty acid

the extracellular matrix is made primarily of which of the following

glycoproteins

which of the following is a stack of flattened thylakoid tubules

granum

in which of the following covalent bonds are electrons considered to be equally shared between atoms

h-h c-c c-h

which of the following are structural formulas

h-h o=o

water tend to repel or exclude _____ molecules

nonpolar

the surface of the nucleus is bounded by 2 phospholipid bilayer membranes called

nuclear envelope

unique among macromolecules, _______ acids are able to serve as templates to produce precise copies of themselves

nucleic

a ribosome consist of a large and small subunit and each contains RNA molecules, which are made in

nucleolus

ionic bonds involve

an attraction between atoms with opposite electrical charges a transfer of electrons from one atom to another

large molecules and particles that cannot cross the hydrophobic barrrier created by the plasma membrane enter or leave the cell by ______

bulk transport

the 2 main categories of _____ ______are endocytosis and exocytosis

bulk transport

how is information stored in a molecule of DNA

by varying the sequence of the 4 types of nucleotides that make up each strand

in order to survive grow and reproduce a cell must

exchange materials and information with its environment

what type of bond can form between 2 identical atoms?

nonpolar

the surface of the nucleus is bounded by 2 phospholipid bilayer membranes, called the ________

nuclear envelope

In order to obtain a stable outer shell of electrons, carbon forms four strong bonds of

covalent

which structure is involved with eukaryote cell division

microtuble organizing center

the function of these fibers of the cytoskeleton include moving materials within the cell and organizing the cytoplasm

microtubles

the structure of ____ is usually discussed in terms of hierarchy of 4 levels

proteins

atoms of the same element always have the same number of ___ and this number is unique for that element

protons

proteins are made up of one or more unbranched chains of

amino acids

when two amino acids are linked together, a peptide bond is formed between the _____ group of one and the ____ group of the other.

amino and carboxyl

which functional group is found in glycerol but not in a fatty acid

hydroxol

if two solutions have unequal concentrations of solutes, the solution with the higher solute concentration is called _______ and the solution with the lower solute concentration is called

hypertonic hypotonic

which type of RNA carries information from DNA

messenger

which of the following best describes the relationship between temperature and enzyme activity

each enzyme has an optimum temperature where it functions best

the volume of space around the nucleus where and electron is most likely to be found is known as

electron orbital

the affinity of an atom for an electron is also known as which of the following

electronegativity

In living organisms, chemical energy is stored in high-energy ____ which can be transferred from one atom to another during redox reactions

electrons

the chemical behavior of an atom depends o the number and configuration of its

electrons

which of the following best describes a contemporary model of electron movement within atoms?

electrons move in orbitals where the probability of finding them is high

a ____ is a substance that cannot be broken down into simpler substances by ordinary chemical means

element

phagocytosis is one of the mechanisms of which of the following

endocytosis

when electrons move closer to the nucleus

energy is released

the letters k, l, m and so on are used to designate different

energy levels in an atom

In living organisms, almost all chemical reactions are catalyzed by protein catalysts called

enzymes

the limitation of resolution for the human eye is how many micrometers.

100

An atom has 11 protons, 12 neutrons and 10 electrons. This atom has an atomic number of ______, and atomic mass of ______, and an overall charge of _____.

11; 23; +1

how many subunits make up a ribosome

2

how are disaccharides formed

2 monosaccharides are linked together through dehydration synthesis

proteins are polymers made up of how many different amino acids

20

if an atom has an atomic number of 6, how many covalent bonds must it form in order to have a stable outer shell of electrons?

4

in a double covalent bond, ____ electrons are shared

4

the diameter of most cells is less than

50 micrometers

an electrically neutral atom has an atomic number of 6 and an atomic mass of 14. this atom has ______ protons, ______ neutrons and _____ electrons.

6, 20; 8

which type of interaction involves the formation of a covalent bond between 2 different amino acid side chains

Disulfide bridge

which of the following statements about a molecule of hydrogen are true

It has no net charge the shared electrons are attracted equally by both nuclei after they bond together, each hydrogen atom has a stable outer shell of electrons it is composed of 2 hydrogen atoms that share one pair of electrons

Water consists of one oxygen atom joined on two hydrogen atoms by which of the following?

Two single polar covalent bonds

a polypeptide is a long, unbranched chain of

amino acids

each kind of protein has a unique sequence of ______ _______

amino acids

Which of the following describes the structure of a phospholipid

a polar head and 2 long nonpolar tails

triglycerides and phospholipids are different because only phospholipids have

a polar head and 2 nonpolar tails a phosphate group attached to one carbon atom in the backbone

in phospholipids, a phosphate is attached to the third carbon of glycerol, what is typically attached to the phosphate

a polar or charged organic molecule

compared to carbon, the electronegativity of hydrogen is

about the same

the carboxyl group is ______ while the amino group is ______

acidic basic

during the contraction of muscle, which fiber is used

actin

identify the fibers which are used in cell division in animals

actin microtubles

which of the following are main points of cell theory

all organisms are composed of one or more cells cells are the smallest living things cells arise only by division of a preexisting cell

how can amino acid side chains affect the structure and function of a protein

amino acid side chains play a role in protein folding amino acid side chains are invloved in catalysis at the active site of enzymes

a chlorine atom that has gained and electron and has an overall negative charge is an example of

anion

atoms with a net negative charge are known as _____, wherease atoms with a net positive charge are known as

anions, cations

a solution where water is the solvent is called a _____ solution

aqueous

of the 2 types of prokaryotes, ______ are abundant throughout the soil, water and the human digestive tract. While ______ are also common, they are typically found in more extreme environments such as hot springs and deep sea thermal vents.

bacteria archaea

which of the following bonds are best described as polar

c-o c-n

which of the following bonds are polar

c-o c-n o-h

which of the following molecules are polar

c2h5oh and h2o

the ability of water to rise inside a tube of narrow diameter against the pull of gravity is called

capillary action

_____atoms form the framework of biological molecules

carbon

which of the following is not a function of intermediate filaments

cell division

identify the functions of actin filaments

certain cell movement pinching of the cell during division cell strength

a chemcal reaction invloves the breaking and formation of

chemical bonds

which of the following are polysaccharides

chitin cellulose glycogen starch

which of the following are correct concerning Eukaryotic DNA structure

chromatin is present the dna is organized in linear chromosomes

_____ are composed of microtubles, but are typically shorter that flagella and tend to cover all or part of the surface of a cell.

cilia

Nitrogenous bases that pair with each other in a DNA molecules are referred to as

complementary

which of the following describe monosaccharides

composed of carbon, hydrogen and oxygen simplest sugars monomers that can be joined together to form more complex carbohydrates

which of the following is true of transmembrane domains

composed of hydrophobic amino acids typically contain configurations of alpha helices

a ___ bond is formed when 2 atoms share one or more pairs of valence electrons.

covalent

what is the term for the region of the cell contained within the plasma membrane

cytoplasm

which of the following are features that ALL cells have in common

cytoplasm ribosomes plasma membrane nucleus

the eukaryotic cell structure involved in supporting the shape of the cell and anchoring organelles to fixed locations

cytoskelton

polymers are formed via chemical reactions termed ____reactions and are broken down by chemical reactions called ____ reactions

dehydration hydrolysis

Carbon-12, carbon-13 and carbon-14 are

different isotopes of the same element

most cell are relatively small for reasons related to the ____ of substances into and out of the cells

diffusion

most cells are relatively small for reasons related to the _____ of substances into and out of the cells

diffusion

net movement of a substance from a region where it has a higher concentration to a region where it has a lower concentration is called

diffusion

the two basic types of secondary structure are ____ helix and ____ sheet.

alpha beta

a hydrogen bond can form between the partially negative _____ atom of one water molecule and the partially positive _____ atom of another water molecule

oxygen hydrogen

the covalent bond that joins 2 amino acids is called a ____ bond.

peptide

archaea cell walls lack

peptidoglycan

most bacterial cells are encased by a strong cell wall composed of ______which is carbohydrate matrix cross linked by polypeptide

peptidoglycan

complex lipids called ______ form the core of all biological membranes

phospholipids

which of the following is not a component of archaea cell walls

phospholipids

which of the following structures are UNIQUE to prokaryote cells

pili nucleoid

what structure surrounds all cells

plasma membrane

a long, unbranched chain of amino acids is called

polypeptide

if two atoms are joined by a polar covalent bond, the atom with the lower electronegativity will have a partial ______ charge.

positive

which of the following contain their genetic material in a nucleoid region

prokaryotes

which of the following are lipids

prostaglandins fats steriods

Ribosomes are responsible for _____ synthesis in the cell

protein

among subatomic particles, each _____ has a charge of +1. each _______ has a charge of -1 and each___ has no charge.

proton electron neutron

Atomic number refers to the number of ______in a atom

protons

which subatomic particles determine the atomic mass of an atom

protons and neutrons

which two particles are the primary determinants of an elements atomic mass?

protons and neutrons

____ isotopes are unstable and tend ot break apart into elements with lower atomic numbers while releasing a significant amount of energy

radioactive

_____ isotopes are often used to label or "tag" specific molecules and then follow their progress either in a chemical reaction or in living cells and tissues.

radioactive

by determining the _____ of the different isotopes of carbon in a sample, scientists are able to accurately determine the age of the sample

ratio

during a chemical reaction, the substances we start out with are called _______ and the substances we end up with are called

reactants and products

an atom participating in a chemical reaction gains one or more electrons. The process of gaining electrons in a reaction is called

reduction

typically, fats found in animals (usually solid) are _____, while fats found in plants (usually liquid) are ____

saturated unsaturated

A hydrogen ion, formed during the disassociation of water, has a charge of which of the following.

+1

which of the following are functions of proteins

they play a key role in moving materials within a cell they catalyze chemical reactions they help the body recognize and destroy foreign microbes and cancer cells they transport oxygen in the blood of vertabrates

during proper base pairing in DNA, adenine pairs with _____ and cytosine pairs with ______

thymine guanine

the purpose of microscopes can best be described as

to allow for visualization of cells and cellular components

the role of the nucleolus is

to produce ribosomal subunits

which type of RNA carries amino acids

transfer

the diffusion of these molecules across a selectivley permeable membrane is called osmosis

water

the most abundant molecule in the cytoplasm is the ____ molecule

water

the surface tension of water is due to which reason

water molecules attract each other

how are ions formed

when atoms lose or gain one or more electrons

the _____ are cellular organelles, which use chemical energy stored within the covalent bonds of organic molecules to produce ATP

mitochondria

which of the following amounts of a substance has a weight in grams equal to the combined atomic masses of all atoms that make up on basic unit of the substance?

mole

one ___ of sucrose contains 6.02 x 10 23 _____ of sucrose

mole and molecules

the simplest carbohydrates are

monosaccharides

a fatty acid with one carbon to carbon double bond is _____ while a fatty acid with two or more carbon to carbon double bonds is _____

monounsaturated polyunsaturated

electrons that are farther from the nucleus always have which of the following

more potential energy

which of the following are acurate statements concerning bacterial flagella

movement is powered by a proton gradient they propel cells forward

which of the following involves active transport

movement of a substance against its own concentration gradient

water carries two partial _____ charges on the oxygen atom and two partial ______ charges, one on each hydrogen atom

negative positive

Isotopes differ in the number of _____ they contain

neutrons

a ____ covalent bond involves and equal sharing of one or more pairs of electrons

non polar

almost all the mass of an atom is located in

nucleus

how do channel and carrier proteins differ

only carrier proteins actually bind to the substance being transprorted only carrier proteins can be used for active transport

match the bases that pair in DNA molecules.

A adenine-thymine B guadine-cytosine

the production of proteins is achieved by

ribosomes

Match each subatomic particle with its electrical charge.

+1, proton 0, nuetron -1, electron

A hydroxide ion has a charge of which of the following?

-1

A group of atoms held together by one or more covalent

...

which of the following describes passive transport

...

a single water molecule can spontaneously break apart (ionize) to form

1 positive hydrogen ion and one negative hydroxide ion

transport that requires a cell to expend some of its own energy, typically from _____,is called _____transport

ATP active

identify the fibers that are used in the cell division of animals

Actin microtubles

how are starch and cellulose SIMILAR

Both are polysaccharides Both are found in plants

what are the 3 major structural components of an amino acid?

Carboxyl group r group amino group

regarding the chemical nature of nitrogenous bases in DNA, which of the following are CORRECTLY matched

Cytosine-pyrimidine Adenine-purine

This molecule stores the genetic code within a given cell

DNA

which of the following molecules have the ability to serve as templates to produce precise copies of themselves

DNA

in living organisms, molecules of _______ are used to store and transmit the genetic information from one generation to the next, while molecules of _______ use the genetic information to actually assemble proteins

DNA RNA

identify the two major classed of nucleic acids

DNA and RNA

describe the structure of DNA

DNA is a double stranded molecule that forms a double helix when the 2 strands wind around one another.

This type of subatomic particle can be found at various distances from the nucleous

Electron

Which of the following are subatomic particles?

Electrons, Neutrons, and Protons

In living systems, which of the following catalyze almost every chemical reaction necessary for life

Enzymes

typically, as the temperature increases, what happens to the rate of a chemical reaction?

It also increases

the 4 main groups of biological micromolecules are

Nucleic acids lipids proteins carbohydrates

Water molecules are attracted to polar molecules, because polar molecules have regions that carry a ________ electrical charge.

Partial

what are the 3 basic components of a nucleotide

Pentose sugar phosphate group nitrogenous base

carbon-oxygen and carbon-nitrogen bonds are described as

Polar covalent formed by an unequal sharing of electrons

how is the crystal structure of salt formed

Positively charged sodium ions are attracted to negatively charged chloride ions

The 3 main types of subatomic particles are

Protons neutrons electrons

All electrically nuetral atoms contain one or more of the following

Protons and electrons

which of the following statements about lipid structure is true?

Steriods are composed of interlocking carbon rings while fats are composed of glycerol and fatty acids. Fats are more similiar in structure to phospholipids than they are to steriods Phospholipids have distinct polar and nonpolar regions Although they may have small polar regions, lipids are mostly nonpolar

triglycerides and phospholipids are similiar because they both have

a backbone derived fri glycerol

which of the following accurately describes the chemical structure of a typical amino acid found in a protein?

a central carbon atom is bound to an amino group, carboxyl group, a side chain and hydrogen atom

when a carbohydrate is formed by linking 2 monosaccarides by a condensation reaction, we get water plus

a disaccharide

which of the following could be the result of a deficiency in chaperons proteins

a disease caused by improper folding of proteins

a defining feature of biological membranes is the presence of

a lipid bilayer

which of the following may occur during a chemical reaction?

existing chemical bonds are broken atoms are transferred from one molecule to another new types of molecules are formed new chemical bonds are formed

which of the following is not one of the 4 main components of all plasma membranes

extracellular matrix

which structure forms a protective layer rich in glycoproteins on the surface of cells

extracellular matrix

which of the following involve passive transport

facilitated diffusion diffusion

Most bacteria are able to cause disease

false

electrons are found in the atom's nucleus

false

the inner or the outer surface of the plasma membrane contain the same type of phospholipids, in similiar proportions

false

during photosynthesis, chloroplasts capture light energy and synthesize which of the following organic material

glucose

which regions of the phospholipid molecule are hydrophilic

glycerol backbone polar or charged molecule attached to the phosphate group phosphate group

which of the following molecules is likely to have the highest specific heat and the highest heat of vaporization

h2o

____ atoms usually have no neutrons

hydrogen

the lightest atom is

hydrogen

which of the following characteristics do lipids share in common

hydrophobic nonpolar

a protein is initially driven into its tertiary structure by ______ _____ of nonpolar groups from water.

hydrophobic exclusion

a catalyst is any substance that ____ the rate of a reaction without being altered itself.

increases

in living systems, ionic compounds generally exist as which of the following

individual ions

if an atom gains or loses electrons, it is known as

ion

unlike _____ bonds, which produce a crystal lattice, ____ bonds are formed between 2 individual atoms, giving rise to true, discrete molecules

ionic covalent

atoms in which the number of electrons does not equal the number of protons are called

ions

in cell membranes,the interior of the lipid layer repels _____

ions hydrophilic molecules polar molecules

organic molecules with the same molecular formula may exist in different forms called

isomers

if 2 solutions have the same concentration of solutes, they are

isotonic

what does it mean when we say water is adhesive

it is attracted to other polar molecules and ions

which of the following statements about receptor-mediated endocytosis is true

its a type of bulk transportation it is used to transport ldls into the cell

which of the following determined the function of a protein molecule.

its shape

Double bonds between carbon atoms cause _____ in the hydrocarbon chains of fatty acids

kinks

when writing out structural formulas, covalent bonds are represented by solid ______ between atomic symbols

lines

Anything that has mass and occupies space is defined as

matter

Regular and repeated patterns of coiling or folding within a polypeptide chain that are due to hydrogen bonding between polar groups within the polypeptide backbone make up which level of the proteins structure

secondary

which of the following statements about orbitals is true

several different orbitals may occupy the same energy level Each orbital contains a maximum of 2 electrons They have a variety of 3d shapes that indicate where an electron is most likely to be found

which of the following about channel proteins is not true

some channel proteins use energy from ATP to facilitate net movement of a substance up its concentration gradient

suppose the concentration of oxygen is higher outside of the cell than inside. which of the following is true

some oxygen molecules will move into the cell the net movement of oxygen will be into the cell some oxygen molecules will move out of the cell

substances that can not easily cross the lipid bilayer can still diffuse across the plasma membrane with the help of

specific channel or carrier proteins

the amount of heat 1g of a substance must absorb or lose to change its temperature by 1 c is called

specific heat

match each plolysaccharide with its function

starch-the main storage polysaccharide in plants cellulose-the main structural polysaccharide in plants chitin-a structural polysaccharide in arthropods and fungi glycogen-the main storage polysaccharide in animals

individual polypeptides within a protein are referred to as

subunits

because of the many hydrogen bonds that form between its molecules, water has a very high _______ ______. this allows small insects to walk on water

surface tension

the ____ of a substance is a measure of how rapidly its individual molecules are moving

temperature

a proteins _____ structure refers to the final 3 D shape of the polypeptide chains that make up the protein

tertiary

Which of the following statements about proteins are true?

the ability of a protein to function depends on its 3 d shape Denatured proteins are usually biologically inactive The shape of a protein is affected by environmental conditions such as temperature, ph and ionic concentration

what is the definition of the heat vaporization of water

the amount of energy needed to change 1g of water from a liquid to a gas

the symbol (H+) means

the molar concentration of hydrogen ions

which regions of a phospholipid bilayer face water and which face the interior of the membrane away from the water

the polar regions face toward the water and the non polar regions face away from the water

what factors contribute to whether a fat is a solid or a liquid at room temperature

the presence of double bonded carbons in fatty acid hydrocarbon chains the degree of packing of fatty acid chains

where are the sugar-phosphate backbones and the nitrogenous bases located in the DNA double helix

the sugar phosphate backbones run along the outside of the double helix while the nitrogenous bases pair the middle

water rises inside a glass tube with narrow diameter for which reason

there are electrical charges on the surface of the glass

water is cohesive. Which describes the water molecules

they are attracted to each other

which of the following is a characteristic that ALL lipids share

they are largely insoluble in water

which of the following characteristics of lipids have in common

they are mostly nonpolar they are hydrophobic

what is the strength of individual hydrogen bonds that form between water molecules

they are very weak

choose all statements that describe phospholipids

they consist of glycerol joined to 2 fatty acids and a phosphate group they spontaneously form micelles or bilayers in water they have a polar head and two nonpolar tails

which describes steroids

they contain 4 interlocking rings they are lipids they are hydrophobic

how can cells allow large polar molecules to enter the cell

they enter through carrier proteins they can enter through channel proteins they can enter through endocytosis

characteristics of phospholipids include

they form the core of biological membranes

why are fats and oils more efficient for storing energy that carbohydrates or proteins

they have a higher ratio of energy storing C-H bonds

which describes most plant fats

they have one or more double bonds between the carbon atoms in the hydrocarbon chains they are liquid at room temperature they are unsaturated

which describes most animal fats

they have only single bonds in their hydrocarbon chains they are saturated they are solid at room temperature

which of the following statements about nonpolar molecules are true

they have the same number of protons and electrons the distribution of electrical charge is uniform they are electrically neutral

which describes steroids ?

they include certain hormones such as estrogen and testosterone they include cholesterol, an important component of animal cell membranes