Honors Biology Midterm Review

science
A body of knowledge about the natural world and a means of acquiring knowledge

scientific method
a method of investigation involving observation and theory to test scientific hypotheses

hypothesis
possible explanation for a set of observations or possible answer to a scientific question

variable
is a changeable factor in an experiment

control experiment
standered of comparison in an experiment; does not contain the variable being tested

experiment
the testing of an idea or hypothesis

data
information gathered from observations during an experiment

theory
a hypothesis that is generally accepted due to LOTS of experimental support

metric system
The system used to measure in a scientific laboratory

meter
a metric unit to measure length or distance (it’s about the same as a yard)

liter
a metric unit of volume

cubic centimeter
also known as 1 cc or 1 mL

mass
the amount of matter in an object

weight
another name for the force of gravity acting on an object

kilogram
A unit of mass equal to 1000 grams.

Celsius scale
a temperature scale that defines the freezing point of water as 0 degrees and the boiling point of water as 100 degrees

unicellular
having or consisting of a single cell

multicellular
consisting of many cells

sexual reproduction
two cells from different parents unite to form the first cell of a new offspring

asexual reproduction
reproduction that does not involve the union of sex cells and in which a single parent produces offspring that are genetically identical to the parent.

anabolism
synthesis of more complex substances from simpler ones

catabolism
breakdown of more complex substances into simpler ones with release of energy

metabolism
combination of chemical reactions through which an organism builds up or breaks down materials as it carries out its life processes

homeostasis
the process by which organsims keep their internal conditions reltively stable

irritability
the ability of living tissue to respond to stimulus

stimuli
What all living things respond to

compound light microscope
microscope that uses light and has two lenses, one in the eyepiece, one in the objective. Magnification goes to 400X on our scopes

limit of resolution
point at which an object can be seen clearly in a microscope, but after this is passed, the object becomes blurry

transmission electron microscope
An electron microscope used to study the internal structure of thin sections of cells

scanning electron microscope
An electron microscope used to study the fine details of cell surfaces

physical property
A characteristic of a substance that can be observed without changing it into another substance.

chemical property
a property used to characterize materials in reactions that change their identity

phase
state inwhich matter exists: solid liquid gas plasma

atom
(physics and chemistry) the smallest component of an element having the chemical properties of the element

nucleus
the positively charged dense center of an atom

proton
positively charged particle found in the nucleus of an atom

neutron
neutral particle found in the nucleus of an atom

electron
negatively charged particle found in energy levels outside of the nucleus of an atom

energy level
a region of an atom in which electrons of the same energy are likely to be found

atomic number
equals the number of protons in the nucle of a atom

mass number
the sum of the number of protons and neutrons in an atoms nucleus

element
pure substance consisting entirely of one type of atom

isotope
atom of the same element that have diffrent numbers of nentrons in their nuclei, but the same number of protons.

compound
a type of matter that cotains two or more chemically combined elements

chemical bonding
the joining of atoms to form new substances. when formed electrons are shared, gained, or lost.

ionic bond
a bond that forms when electrons are transferred from one atom to another,which results in a positive ion and a negative ion.

ion
An atom that has gained or lost electrons, thus acquiring a charge.

covalent bond
A bond whose electrons are shared between atoms

molecule
(physics and chemistry) the simplest structural unit of an element or compound

chemical reaction
a change in which one or more reactants change into one or more products; characterized by the breaking of bonds in reactants and the formation of bonds in products

mixture
two or more elements or compounds that are physically mixed but not chemically combined

solution
mixture of 2 or more substances that is homogeneous; consists of a solute and a solvent

solvent
Substance that does the dissolving

solute
What is being dissolved

acid
releases hydrogen ions (H+); a chemical with a pH less than 7

base
releases hydroxide atoms (OH-); a chemical with a pH more than 7

neutralization reaction
the reaction of an acid and a base to form a neutral solution of water and salt

pH scale
measures the concentration of Hydrogen ions in solution, ranges from 0-14

suspension
a mixture in which particles can be seen and easily seperated by settling of filtration is a

organic compound
a compound whose large molecules contain carbon

inorganic compound
a compound whose large molecules do NOT contain carbon

polymerization
the process of joining monomers together to make polymers

monomer
A small molecule that connects together to form polymers.

polymer
A long molecule consisting of many similar or identical monomers linked together.

macromolecule
made in living systems from smaller building blocks covalently bonded; four classes: proteins, nucleic acids, carbohydrates, and lipids

carbohydrate
a class of molecules ranging from the small sugar molecules dissolved in soft drinks to large polysaccharides, such as the starch molecules

monosaccharide
single sugar monomers

dehydration synthesis
A chemical reaction in which two molecules covalently bond to each other with the removal of a water molecule.

disaccharide
2 monosaccharides, linked using dehydration synthesis

polysaccharide
A polymer of up to over 1000 monosaccharides, formed by dehydration reactions.

hydrolysis
A chemical process that lyses, or splits, molecules by the addition of water.

lipid
macromolecules used for energy storage, cell membranes, and waterproofing

cholesterol
a sterol produced only by animals

protein
has monomers made of amino acids

amino acid
An organic molecule possessing both carboxyl and amino groups. Serve as the monomers of proteins.

peptide bond
covalent bond formed between amino acids

catalyst
a substance that speeds up the rate of a chemical reaction

enzyme
a type of protein that speeds up the rate of chemical reaction in your body

nucleic acid
macromolecules that store and transmit hereditary, or genetic, information

nucleotide
The building block of a nucleic acid, consisting of a five-carbon sugar covalently bonded to a nitrogenous bas and a phosphate group.

RNA
A single-stranded nucleic acid that passes along genetic messages taken from DNA

DNA
the double stranded molecule that contains the genetic code

cell
The microscopic, living building blocks that every living thing is made up of

cell theory
all living thing composed of cells, cells are the basic units of structure and function in living things, new cells produced from existing cells

cell membrane
thin, flexible barrier around a cell, regulates what enters and leaves the cell

cell wall
strong layer around the cell membrane in plants, algae, and some bacteria

nucleus
Contains DNA chromosomes, control center of the cell, contained in the nuclear envelope, nucleolus makes RNA.

eukaryote
organism with a nucleus

prokaryote
organism without a nucleus

nuclear envelope
double membrane perforated with pores that control the flow of materials in and out of the nucleus

nucleolus
structure inside the nucleus, where ribosomes are made

chromosome
a threadlike body in the cell nucleus that carries the genes in a linear order

cytoplasm
a jellylike fluid inside the cell in which the organelles are suspended

organelle
membrane bound structure inside a cell that performs a specific function

mitochondrion
an organelle containing enzymes responsible for producing energy

chloroplast
organelle in plant cells that converts the energy in sunlight into sugars

ribosome
small particle of RNA and protein that produces protein following instructions from nucleus

endoplasmic reticulum
a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another

Golgi apparatus
Organelle that modifies, sorts, and packages proteins from the endoplasmic reticulum and send proteins to their final destination

lysosome
structure that breaks down food particles and worn out cell part

vacuole
storage structures for food, water, minerals, waste

plastid
stores food or contains pigment in plant cells (leukoplast is an example)

cytoskeleton
A network of microtubules, microfilaments, and intermediate filaments that branch throughout the cytoplasm and serve a variety of mechanical and trasport functions.

diffusion
movement of particles from an area of high concentration to an area of lower concentration

selectively permeable
when some substances can pass through a membrane easily when others cannot

osmosis
The diffusion of water across a selectively permeable membrane.

facilitated diffusion
when substances transport across cell membranes using protein carrier molecules

active transport
to pump a molecule across a membrane agaist its gradient requires work; the cell must expend energy

cell specialization
cells are uniquely suited to perform a particular function

tissue
group of similar cells that perform a paritcular function

organ
composed of two or more tissue types and performs a specific function for the body

organ system
A group of organs that work together in performing vital body functions.

photosynthesis
plants use the energy of sunlight to convert water and carbon dioxide into oxygen and high-energy carbohydrates

glucose
A sugar molecule made by producers during photosynthesis and “burned” by all organisms during respiration to make energy.

autotroph
an organim that makes its own food.

heterotroph
gets energy from eating other living things such as autotrophs

pigment
in plants, a compound that absorbs light and imports color

chlorophyll
green pigment in plants that absorbs light energy used to carry out photosynthesis

ATP
adenosine triphosphate – what the cell uses for energy

light reaction
the first stage of photosynthesis during which energy from light is used for the production of ATP and NADPH

dark reaction
the second stage of photosynthesis that starts with ATP, NADPH, and Carbon dioxide and produces glucose

photosystem
Light-collecting units of the chloroplast

electron transport chain
the series of molecules through which excited electrons are passed along a thylakoid membrane

Calvin cycle
uses ATP and NADPH from the light-dependent reactions to produce glucose; also known as the dark reaction in photosynthesis

glycolysis
1st step in realeasing the energy of glucose, in which a molecule of glucose is broken into 2 molecules of pyruvic acid.

respiration
the process by which most living things break food down into energy when oxygen is present

aerobic
Presence of oxygen

Krebs cycle
second stage of cellular respiration, in which pyruvic acid is broken into carbon dixide in a series of energy extracting reactions; also called Citric Acid Cycle

fermentation
process by which cells release energy in the absence of oxygen

anaerobic
Absence of oxygen

lactic acid fermentation
the type of fermentation that creates lactic acid and gives muscle cells a weak and sore sensation

alcoholic fermentation
the process of breaking down sugars and creating alcohol, carbon dioxide, and a small amount of energy in yeasts and other microorganisms