Biology Module 6 Test

What is the ratio of carbohydrates in a monosaccharide?

1 carbon: 2 hydrogen: 1 oxygen

How do enzymes affect the speed of chemical reactions in the body?

it speeds it up

What happens to the speed of a chemical reaction when a catalyst is present?

it speeds up

macromolecule

large molecule formed by joining smaller organic molecules together

proton

positively charged particle in an atom's nucleus

Carbohydrates functions

provide energy

Lipid functions

store energy

Van der Waals forces

attractive forces between molecules

Which biological macromolecule is not considered a polymer?

a lipid

Homogenous

a mixture that has a uniform composition thought

Which of the following is an atom that has lost an electron?

a positive ion

Which of the following can be classified as a van der Waals force?

a weak electrostatic interaction between two polar molecules

Which property of water helps plants to transport water from their roots to their leaves?

adhesion

What is a radioactive isotope?

an atom whose nucleus is unstable and emits particles and energy

ion

atom that is negatively or positively charged because it has lost or gained one or more electrons

Bond energy is the amount of energy it takes to break a bond between two ___

atoms

atom

building blocks of matter; contains subatomic particles neutrons, protons, and electrons

Protein functions

building blocks of protein

What are the major classes of biological macromolecules?

carbohydrates, proteins, lipids, nucleic acid

amino acid

carbon compound joined by peptide bonds; building block of proteins

Which of the following can reduce the amount of energy needed for a chemical reaction to take place?

catalyst

nucleus

center of an atom; contains neutrons and protons

During a chemical reaction ___ break and reform

chemical bonds

endothermic reactions

chemical reaction that absorbs more energy that it releases

exothermic reactions

chemical reaction that release more energy than it absorbs

Which property causes water to from beads?

cohesion

mixture

combination of 2 or more different substances

nucleic acid

complex macromolecule that stores and communicates genetic information

molecule

compound whose atoms are held together by covalent bonds

water and carbon dioxide are examples of ____

compounds

A molecule is held together by ___

covalent bonds

A catalyst can ____ the amount of energy needed to start a chemical reaction

decrease

Which of the following compounds are examples of nucleic acids?

deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

ionic bond

electrical attraction between 2 oppositely charged atoms or groups of atoms

Which of the following is not found in the nucleus of an atom?

electron

Which process changes a chlorine atom into a negative chloride ion?

electron gain

Two atoms may form several covalent bonds to share several pairs of _____

electrons

____ are made up of only one type of atom

elements

Chemical reaction

energy requiring process by which atoms or groups of atoms in substances are reorganized into different substances

Substrates are to____ as keys are to locks.

enzymes

Which of the following compounds can be classified as a proteins?

enzymes

____ are catalysts for chemical reactions in living things

enzymes

A solution is a mixture of substances that is ____ disturbed through the entire mixture

evenly

Scientists make observations and do experiments as a way to gather ___

evidence

A theory is a specific idea that has been proven to be true

false

An atom becomes an ion when its number of proton changes

false

Carbon's outer energy level is full

false

Not all chemical reactions involve changes in energy

false

Polar molecules have two regions with a light positive charge

false

Some ions are positively charged, and some ions have no changes

false

The three basic structures of carbon-based molecules are straight chain, bent chain, and ring chain

false

an exothermic chemical reaction absorbs more energy that it releases

false

chemical reactions can occur whether or not energy is added to the reactants

false

Which of the following are potential applications of radioactive isotopes?

food preservation, fossil dating, cancer treatment, medical imaging

Which of the following functions can be attributed to nucleic acids and nucleotides?

genetic information storage and transmission

Vertical rows are called?

groups

Which property allows water to resist changes in temperature?

high specific heat

solution

homogenous mixture formed when a substance is dissolved in another substance

activation energy

minimum amount of energy needed for reactants to form products in a chemical reaction

buffer

mixture that can react with an acid or a base to maintain in the pH within a specific range

polar molecule

molecule with oppositely charged regions

electron

negatively charged particle that occupies space around an atoms nucleus

Oil and water don't mix because ____ molecule can't easily dissolve in a polar molecule

nonpolar

DNA and RNA are nucleic acids polymers that are made up of?

nucleotides

A scientist begins his or her research by making _____ theories

observations

protein

organic compound made of amino acids joined by peptide bonds; primary building block of organisms

carbohydrates

organic compounds containing carbon, hydrogen, and oxygen in a ratio of one oxygen and two hydrogen atoms foe each carbon atom

Shared pairs of electrons fill the ___ energy levels of bonded atoms

outermost

Acids have

pH values < 7

Bases have

pH values >7

Which of the following factors influence enzyme activity?

pH, temperature

neutron

particle without a charge in an atoms nucleus

Which of the following joins amino acids together?

peptide bonds

Horizonal rows are called?

periods

Carbohydrates that provide structural support, like chitin, are usually?

polysaccharides

activation energy is the energy required to?

start a chemical reaction

Which of the following compounds can be classified as lipids?

steroids, unsaturated fatty acids, saturated fatty acids, phospholipids

Covalent bonds are generally very ____

strong

product

substance formed by a chemical reaction; located on the right side of the arrow in a chemical equation

solvent

substance in which another substance is dissolved

acid

substance that releases hydrogen ions (H+) when dissolved in water; an acidic solution has a pH less than 7

base

substance that releases hydroxide ions (OH-) when dissolved in water; a basic solution has a pH greater than 7

reactant

substances that exists before a chemical reaction starts; located on the left side of the arrow in a chemical equation

solute

substances that is dissolved in solvent

catalyst

substances that speeds up a chemical reaction by reducing the activation energy

What physical factors affect the action of enzymes?

temperature and pH

How are water molecules in a rain drop held together?

van der Waals forces

Quantitive data

volume, mass, tempature

hydrogen bond

weak electrostatic bond formed by the attraction of opposite charges between a hydrogen atom and an oxygen, fluorine, or nitrogen atom

active site

specific place where a substance binds on an enzymes

nucleotide

A subunit of nucleic acid formed from a simple sugar, a phosphate group, and a nitrogenous base.

Why is the active site of an enzyme important to enzyme activity?

It allows the enzyme to catalyze very specific reactions.

How does a substrate affect an enzyme?

It binds and makes it possible for the reaction to take place

Which of the following is not a property of water?

It combusts

Which properties of water make it a compound necessary for life to exist on our planet?

Its solid form is less dense than its liquid form; ice floats, It is an excellent solvent, It is adhesive and cohesive, It is a polar molecule capable of forming hydrogen bonds.

Qualitative data

Sounds, smells, sights

Why is the sequence of amino acids important to protein function?

The order of amino acids determines the shape a protein will take.

lipid

hydrophobic biological molecule composed mostly of carbon and hydrogen; fats, oils, and waxes

Where do enzymes act as catalyst?

in living things

polymer

large molecule formed from smaller repeating units of identical, or nearly identical, compounds linked by covalent bonds

Nucleic acid functions

map for making proteins

Which of the following functions can be attributed to lipids?

membrane and barrier formation, energy storage, building blocks for cholesterol and other hormones

enzyme

proteins that speeds up a biological reaction by lowering the activation energy needed to start the reaction

element

pure substance composed of only one type of atom; cannot be broken down into another substance by physical or chemical means

compound

pure substance with unique properties; formed when two or more different elements combine

substrate

reactant to which an enzyme binds

___ are the substances changed during a chemical reaction

reactants

Which statement is true of chemical equations?

reactants come before the arrow, products come after.

Equilibrium occurs when reactants and products are made at the ___

same rate

Which of the following molecules can be identified as carbohydrates?

simple sugars, disaccharides, glucose, polysaccharides

A ____ dissolves in a solution

solute

Blood plasma is an example of a

solvent

Heterogenous

the components in a mixture remain distant

pH

the measure of concentration of hydrogen atoms (H+) in a solution

Why are intermolecular forces, such as van der Waals forces, important to biological function? Multiple choice question.

they are easy to form and break apart, making them ideal for short-term interactions.

How do enzymes affect a chemical reaction, making it easier to occur?

they reduce the activation energy.

Carbon atoms can form covalent bonds with up to four atoms

true

Carbon atoms form the building blocks of most living things

true

Ions usually form when electrons are transferred from one atom to another

true

Slightly charged regions of water molecules form hydrogen bonds

true

The formation of an ion results in a full outermost energy level

true

Water is a polar molecule

true

activation energy is required for a chemical reaction to start

true

some chemical reactions release more energy than they absorb, while others absorb more energy than they release

true

theories can change over time as new evidence is discovered

true

isotope

two or more atoms of the same element having different numbers of neutrons

covalent bond

type of chemical bond formed when atoms share electrons