Biology Chapters 1 and 2 Practice Flashcards

Vocabulary-style flashcards covering the key concepts from Chapters 1 and 2, including biological levels of organization, characterstics of life, basic chemistry, and the four macromolecules of life.

Atom

The smallest chemical unit of a type of pure substance; the smallest possible piece of an element composed of protons, neutrons, and electrons.

Molecule

A group of joined atoms; specifically two or more atoms joined by chemical bonds.

Organelle

A membrane-bounded structure that has a specific function within a cell.

Cell

The basic units of life.

Tissue

a group of similar cells working together to perform a specific function

Organ

structure of tissues organized to carry out specific functions.

Organ system

Organs connected physically or chemically that function together.

Organism

A single living individual.

Population

A group of the same species of organism living together.

Community

All populations that occupy the same region.

Ecosystem

The living and nonliving components of an area.

Biosphere

The global ecosystem; the parts of the planet and its atmosphere where life is possible.

DNA

A molecule that carries genetic information; all cells use it to produce proteins.

Emergent properties

where single components react to do something new.

Primary producers

Organisms that extract energy and nutrients from the nonliving environment.

Consumers

Organisms that obtain energy and nutrients by eating other organisms.

Decomposers

Consumers that obtain nutrients from dead organisms and organic waste.

Homeostasis

A state of internal constancy in the presence of changing external conditions.

Asexual reproduction

Form of reproduction in which offspring arise from only one parent, making all offspring nearly identical.

Sexual reproduction

The combination of genetic material from two individuals to create a third individual.

Growth

An increase in an organism's size, generally via cell division.

Development

Changes that occur as an organism matures, including growth, cell specialization, and other processes.

Natural selection

enhanced reproductive success of certain individuals based on inherited characteristics.

Taxonomy

The science of naming and classifying organisms.

Genus

Closely related species grouped together.

Species

The basic unit of classification.

Prokaryotes

Organisms where DNA is free in the cell and not confined to a nucleus; includes domains Bacteria and Archaea.

Eukaryotes

Unicellular or multicellular organisms whose cells contain a nucleus.

Matter

Any material that takes up space.

Energy

The ability to do work or move matter.

Element

A pure substance consisting of atoms containing a characteristic number of protons.

Nucleus (of an atom)

The central part of an atom containing protons and neutrons.

Proton

A particle in an atom's nucleus with a positive charge; the number of these determines which element an atom is.

Neutron

A particle in an atom's nucleus that is electrically neutral.

Electron

A negatively charged particle that orbits the nucleus of an atom.

Atomic number

The number of protons in the nucleus of an atom.

Ion

An atom or group of atoms that has lost or gained electrons, giving it an electrical charge.

Cation

A positively charged ion.

Anion

A negatively charged ion.

Mass number

The sum of protons + neutrons in the nucleus.

Isotope

Any of the forms of an element, each having a different number of neutrons in the nucleus.

Atomic weight

The average mass of all atoms of an element.

Radioactive isotope

An atom that emits particles or rays as its nucleus disintegrates.

Compound

A molecule including different elements.

Valence Shell

The outermost electron shell of an atom, containing the electrons farthest from the nucleus.

Valence

The bonding capacity of an atom determined by the number of electrons needed to fill or balance its valence shell.

Covalent bond

A bond formed when atoms share electrons to achieve a stable, balanced state.

Non polar covalent bonds

Bonds where electrons are shared between atoms equally.

Polar covalent bonds

Bonds where electrons are shared between atoms but not equally, as one atom has a stronger pull.

Hydrogen bonds

Bonds formed because of the weak electrostatic attraction between the opposite charges of neighboring polar molecules.

Ionic bonds

Bonds formed when an atom completely gains or loses electrons.

Cohesion

The tendency of water molecules to stick together.

Adhesion

The tendency of water molecules to form hydrogen bonds with substances other than water.

Solvent

Chemicals in which other substances dissolve.

Solutes

The substances being dissolved into solvents

Dehydration synthesis

A chemical reaction where two monomers are joined to form a larger molecule by losing a water molecule.

Hydrolysis

A chemical reaction where a larger polymer is broken down into individual monomers by introducing a water molecule.

Monomers

building blocks for larger molecules.

Polymers

Large molecules made by bonding many monomers together

pH

A measure of the number of hydrogen ions in a solution.

Acidic

more hydrogen ions than hydroxide ions, pH less than 7

Basic/alkaline

A solution with a pH greater than 7

Neutral

A solution with a $pH = 7$.

Buffers

keep pH at the relatively the same level

Carbohydrates

Molecules with monosaccharide monomers; provide immediate, rapid energy for cellular processes.

Lipids

Molecules typically made of glycerol and fatty acids; they function as long-term energy storage.

Proteins

Molecules with amino acid monomers. speed up and catalyze chemical reactions inside a cell.

Nucleic acids

Molecules with nucleotide monomers that store genetic information.

Nucleotide

A monomer consisting of a Five-Carbon sugar, a phosphate group, and a nitrogenous base.

R group

The part of the amino acid that distinguishes the $20$ types from one another and determines their chemical properties.

Primary structure

The specific linear sequence of amino acids in the polypeptide chain.

Secondary structure

Localized, repeated coils, sheets, or loops formed by hydrogen bonds between the atoms of the polypeptide backbone.

Tertiary structure

The overall three-dimensional shape of a single polypeptide chain.

Quaternary structure

multiple individual polypeptide chains working together as a single functional protein.

Triglcerides

One of the four types of lipids.

Saturated Fats

Fats containing all possible hydrogen atoms with single bonds connecting carbons; are solid at room temperature.

Unsaturated Fats

Fats containing at least one double bond between carbons, creating kinks in the tails; they are liquid at room temperature.

Monosaccharides

Smallest carbohydrates consisting of a single sugar ring (e.g., glucose, fructose); used for immediate energy.

Disaccharides

Simple sugars consisting of two monosaccharides joined by dehydration synthesis (e.g., sucrose, lactose).

Polysaccharides

Complex carbohydrates consisting of hundreds or thousands of monomers linked together; used for long-term energy storage