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.