Biology Chapter 2

Hydrogen bond

Weak attraction between a hydrogen atom and another atom.

What molecule is made up of glycerol and fatty acids?

lipids

ion

Atom that has a positive or negative charge.

Identify three major roles of proteins.

1) they control the rate of reactions and regulate cell processes 2) form important cellu.ar structures 3) transport substances into or out of cells or help fight disease

Nucleotides consist of a phosphate group, a nitrogenous base, and a

5-carbon sugar

How are acids and bases different? How do their pH values differ?

Acids form H+ ions in a solution and have a pH value below 7. Bases produce OH- in a solution and have a pH value above 7.

How are the acids and bases different? How do their pH values differ?

Acids have more hydrogen ions (H+) than hydroxide ions (OH-) and have a pH of below 7. Bases have more hydroxide ions (OH-) than hydrogen ions (H+) and have a pH above 7 The lower the pH, the greater the acidity

Explain the relationship between atoms, elements, and compounds

An atom is the smallest form of matter. An element is a pure substance consisting of entirely one type of atom (H - Hydrogen). A compound is formed by the combination of two or more elements in definite proportion (H2O)

What relationship exists between an enzyme and a catalyst?

An enzyme IS a catalyst.

What is a radioactive isotope? Describe two scientific uses of radioactive isotopes.

An isotope is radioactive if it's nuclei is unstable and breaks down at a constant rate over time. Geologists use them to determine the ages of rocks and fossils. They can also be used to detect and treat cancer.

Explain the relationship between atoms, elements and compounds.

Atoms join together to form elements, elements join together to form compounds.

Cohesion

Attraction between molecules of the same substance.

Why is it important for cells to buffer solutions against rapid changes to pH?

Buffers play an important role in maintaining homeostasis in organisms.

What are the functions of each of the four groups of macromolecules?

Carbohydrates - main source of energy and for structural purposes. Lipids - used to store energy; important parts of biological membranes and waterproof coverings. Nucleic acids - store and transmit hereditary or genetic information. Proteins - control rate of reactions and regulate cell processes, form important cellular structures and transport substances into/out of cells or fight disease.

What elements does carbon bond with to make up life's molecules?

Carbon can combine with many elements, including hydrogen, oxygen, phosphorous, sulfur and nitrogen to form molecules of life.

ionic bond

Chemical bond formed when one or more electrons are transferred from one atom to another.

What happens to chemical bonds during chemical reactions?

Chemical reactions always involve changes in the chemical bonds that join atoms in compounds.

Describe the two types of energy changes that can occur in a chemical reaction.

Chemical reactions either release energy or absorb energy.

How do energy changes affect whether a chemical reaction will occur?

Chemical reactions that release energy often occur spontaneously. Chemical reactions that absorb energy will not occur without a source of energy.

Explain the properties of cohesion and adhesion. Give an example of each.

Cohesion is an attraction between molecules of the same substance. Adhesion is an attraction between molecules of different substances. Cohesion is what causes water to bead on glass shower walls. Adhesion is what causes water to climb up a paper towel that is dipped in water.

Explain the properties of cohesion and adhesion. Give an example of each property.

Cohesion is the attraction of molecules of the same substance and adhesion is the attraction of molecules of different substances. Cohesion causes water to form into droplet. Adhesion causes them to stick to the glass of your shower door.

Carbohydrate

Compound made up of carbon, hydrogen, and oxygen atoms; type of nutrient that is the major source of energy for the body.

acid

Compound that forms hydrogen ions (H+) in solution; a solution with a pH of less than 7.

buffer

Compound that prevents sharp, sudden changes in pH.

base

Compound that produces hydroxide ions (OH-) in solution; solution with a pH of more than 7.

Amino acid

Compound with an amino group on one end and a carboxyl group on the other end.

Identify three major roles of proteins.

Control the rate of reactions and regulate cell processes. Form important cellular structures such as bones. Help fight disease.

Solvent

Dissolving substance in a solution

Product

Element or compound produced by a chemical reaction.

Reactant

Element or compound that enter into a chemical reaction.

Activation energy

Energy that is needed to get a reaction started.

What relationship exists between an enzyme and a catalyst?

Enzymes are proteins that act as a biological catalyst (Nature's catalyst). Enzymes lower the activation energy and speed up the reaction time.

What role do enzymes play in living things and what affects their function?

Enzymes speed up chemical reactions that take place in the cells. Temperature, pH and regulatory molecules can affect their function.

Adhesion

Force of attraction between different kinds of molecules.

Distinguish between single, double and triple covalent bonds.

If a bond shares two electrons it is a single covalent bond, four is a double and six is a triple.

How do isotopes of the same elements differ?

In number of neutrons and in mass

What are the main types of chemical bonds?

Ionic bonds and covalent bonds

Explain the relationship between monomers and polymers, using polysaccharides as an example.

Just as monomers join together to form polymers, monosaccharides join together to form polysaccharides.

Nucleic acid

Macromolecule containing hydrogen, oxygen, nitrogen, carbon, and phosphorus.

Lipid

Macromolecule made mostly from carbon and hydrogen atoms; includes fats, oils, and waxes.

Protein

Macromolecule that contains carbon, hydrogen, oxygen, and nitrogen; needed by the body for growth and repair.

Mixture

Material composed of two or more elements or compounds that are physically mixed together but not chemically combined.

Suspension

Mixture of water and non dissolved material.

Polymer

Molecule composed of many monomers; makes up macromolecules.

electron

Negatively charged particle; located in the space surrounding the nucleus.

Describe the parts of a nucleotide.

Nucleotides consist of three parts: a 5-carbon sugar, a phosphate group (-PO4), and a nitrogenous base.

isotope

One of several forms of a single element, which contains the same number of protons but different numbers of neutrons.

Chemical reaction

Process that changes, or transforms, one set of chemicals into another set of chemicals.

Enzyme

Protein catalyst that speeds up the rate of specific biological reactions.

What three subatomic particles make up atoms?

Protons, neutrons and electrons

element

Pure substance that consists entirely of one type of atom.

Substrate

Reactant of an enzyme-catalyzed reaction.

pH scale

Scale with values from 0 to 14, used to measure the concentration of H+ ions in a solution; a pH of 0 to 7 is acidic, a pH of 7 is neutral, and a pH of 7 to 14 is basic

Monosaccharide

Simple sugar molecule.

van der Waals forces

Slight attraction that develops between oppositely charged regions of nearby molecules.

Monomer

Small chemical unit that makes up a polymer.

molecule

Smallest unit of most compounds that displays all the properties of that compound.

compound

Substance formed by the chemical combination of two or more elements in definite proportions.

Solute

Substance that is dissolved in a solution.

Catalyst

Substance that speeds up the rate of a chemical reaction.

Nucleotide

Subunit of which nucleic acids are composed; made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base.

Describe some factors that may influence enzyme activity.

Temperature, pH and regulatory molecules can affect enzyme activity.

Describe how the atoms in a compound are held together

The atoms in a compound are held together by chemical bonds. Either "ionic bonds" (formed when one or more electrons are 'transferred' from one atom to another) or "covalent bonds" (formed when atoms 'share' electrons instead of transferring them).

Describe how the atoms in a compound are held together.

The atoms in a compound are held together by chemical bonds. Ionic or covalent are the two main types of chemical bonds.

atom

The basic unit of matter.

nucleus

The center of an atom.

Describe the parts of a nucleotide.

The parts of a nucleotide are a 5-carbon sugar, a phosphate group and a nitrogenous base.

In what ways do compounds differ from their component elements?

The physical and chemical properties of a compound are usually very different from those of the elements from which it is formed.

How would the pH of a buffered solution change with the addition of a strong base (pH 14)?

The solution's pH would remain relatively stable.

What is the relationship between solutions, solutes and solvents.

The solvent dissolves the solute to create the solution.

In a salt solution, what happens to sodium and chloride ions?

They become evenly dispersed in the water.

How are all of the isotopes of an element similar?

They have the same chemical properties because they have the same number of electrons.

covalent bond

Type of bond between atoms in which the electrons are shared.

Solution

Type of mixture in which all the components are evenly distributed.

How does the structure of water contribute to its unique properties?

Water is a polar molecule which allows it to form multiple hydrogen bonds.

How does water's polarity influence its properties as a solvent?

Water polarity gives it the ability to dissolve both ionic compounds and other polar molecules.

Explain the relationship between monomers and polymers, using polysaccharides as an example.

When monomers join together they form polymers. Therefore, monosaccharides (simple sugars) join together to form polysaccharides (complex carbohydrates).

What describes a group of different species that live together in a defined area?

a community

What are the physical or non-living components of an ecosystem called?

abiotic factors

A compound that produces hydrogen ions in solution is a(n)

acid

In a chemical reaction, a reactant binds to an enzyme at a region known as the

active site

Proteins are polymers formed from

amino acids

Proteins and carbohydrates are similar in that both

are polymers containing carbon, hydrogen and oxygen

Nutrients move through an ecosystem in

biogeochemical cycles

Biogeochemical cycles involve cycling matter through

biological processes, geological processes and chemical processes

The total amount of living tissue at each trophic level in an ecosystem can be shown in a(n)

biomass pyramid

When biologists refer to ecology on a global scale, they use the term

biosphere

The group of macromolecules that serves as the main source of energy for living things is

carbohydrates

What is the key building block of living tissue and ecosystems?

carbon

When organisms use chemical energy to produce carbohydrates, the process is called

chemosynthesis

A biogeochemical cycle is a(n)

closed loop that describes how elements pass through parts of the biosphere

Two or more different atoms are combined in definite proportions in any

compound

Organisms that cannot harness their own energy are called

consumers

An example of a producer is

corn in a field

Which types of organisms recycle nutrients in a food web?

decomposers and detritivores

In polar molecules such as water, there is an uneven distribution of

electrons

Ion bonds form when

electrons are transferred from one atom to another.

The one-way movement of energy through an ecosystem is best described as a

food chain

The series of steps in which a large fish eats a small fish that has eaten algae is a

food chain

A set of complex feeding relationships in which a single organism might be both a primary and secondary consumer is best shown using a(n)

food web

Describe how ALL consumers get their energy.

from eating organisms that are living or were once living.

Compared to most other substances, a great deal of heat is needed to raise the temperature of water by a given amount. This is because water

has a high heat capacity.

Ecology focuses on

how organisms relate to each other and their environment.

The attraction between the hydrogen atom on one water molecule and the oxygen atom on another water molecule is called a(n)

hydrogen bond

An ecological pyramid...

illustrates trophic levels in an ecosystem

Chemical bonds that involve the total transfer of electrons from one atom or group of atoms to another are called

ionic bonds

An enzyme speeds up a reaction by

lowering the activation energy.

Why is a food web a better model than a food chain for showing feeding relationships?

many animals eat more than one kind of food

A population includes all

members of one species in an area

When you shake sugar and sand together in a test tube, you cause them to form a

mixture

Which method do ecologists rely primarily on when studying ecological events occurring at a global scale over long periods of time?

modeling

The group of macromolecules that stores and transmits genetic information is

nucleic acids

Organisms that consume a variety of foods including plants and animals are called

omnivores

Which of the following nutrients is NOT found in large quantities in the atmosphere? carbon nitrogen phosphorous oxygen

phosphorous

What biogeochemical cycle does NOT include a major path in which the substance cycles through the atmosphere?

phosphorous cycle

The most common primary producers harness energy through

photosynthesis

A group of individuals that belong to a single species and that live together in a defined area is termed a(n)

population

The positively charged particle in an atom is called

proton

All atoms of the same element contain the same number of

protons

What two subatomic particles form the nucleus of an atom?

protons and neutrons

The elements or compounds that enter into a chemical reaction are called

reactants

The major functions of proteins in cells include

regulating cell processes, transporting substances and controlling reactions

If a reaction in one direction releases energy, the same reaction in the other direction

requires energy

A covalent bond is formed by the

sharing of electrons

What are sources of energy for Earth's living things?

sunlight and chemical energy

All of life on Earth exist in

the biosphere

After a substrate binds to an enzyme

the enzyme can start the reaction again once the products are released.

As an analogy, the monomers in a polymer are like

the links in a chain

The elements or compounds formed by chemical reactions are

the products

Isotopes of an element contain

the same number of protons but a different number of neutrons.

Water can enter the atmosphere by evaporating from the leaves of plants in the process of

transpiration

Primary producers are organisms that

use energy they take in from the environment to convert inorganic molecules into complex organic molecules.

Chemical reactions that absorb energy

will not occur without a source of energy.