Pre Ap Biology Final

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

Interphase

Cell grows, performs its normal functions, and prepares for division; consists of G1, S, and G2 phases

Prophase

Chromosomes become visible, nuclear envelop dissolves, and spindle forms

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Telephase

spindle fibers disassemble and the chromosomes return to a less tightly coiled chromatin state

Cytokenis

the division of the cytoplasm to form two separate daughter cells after mitosis

Chromosomes

a threadlike structure of nucleic acids and proteins found in the nucleus of most living cells, carrying genetic information in the form of genes.

Centromere

Region of a chromosome where the two sister chromatids attach

Chromatids,

one of two identical "sister" parts of a duplicated chromosome

S phase

The synthesis phase of the cell cycle; is the portion of interphase during which DNA is replicated.

G1 phase

The first gap, or growth phase, of the cell cycle, consists of the portion of interphase before DNA synthesis begins.

G2 phase

The second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs.

Diploid

containing two complete sets of chromosomes, one from each parent.

Haploid

having a single set of unpaired chromosomes

homologous chromosomes

Pair of chromosomes that are the same size, same appearance and same genes.

Protozoa

one-celled organisms that are more complex than bacteria

Virus

A tiny, nonliving particle that invades and then reproduces inside a living cell.

Bacteria

single-celled organisms that lack a nucleus; prokaryotes

Flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Photosynthesis

Conversion of light energy from the sun into chemical energy.

Choroplast

tiny structure in plant cells where the plant converts the sun's energy into chemical energy

Chlorophyll

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

Respiration

The process by which cells break down simple food molecules to release the energy they contain.

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Glycolysis

A metabolic process that breaks down carbohydrates and sugars through a series of reactions to either pyruvic acid or lactic acid and releases energy for the body in the form of ATP

Krebs cycle

The second stage of cellular respiration, in which pyruvic acid is broken down into carbon dioxide in a series of energy-extracting reactions

Anaerobic

Process that does not require oxygen

NADH and FADH2

high energy electron carrier(s) after reduction in cellular respiration (after they pick up electrons from Kreb's cycle)

Fermentation

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

lactic acid

Produced in muscle cells from the reduction of pyruvate (under anaerobic conditions) to regenerate NAD+ so that glycolysis can continue. A rise in lactic acid usually accompanies an increase in physical activity.

yeast

single celled fungi

Enzyme

protein that acts as a biological catalyst

enzyme-substrate complex

A temporary complex formed when an enzyme binds to its substrate molecule(s).

Substrate

The reactant on which an enzyme works.

active site

the region on the enzyme where the substrate binds

activation energy

The energy needed to get a reaction started

ATP

(adenosine triphosphate) main energy source that cells use for most of their work

Macromolecules

A very large organic molecule composed of many smaller molecules

Monomer

A simple compound whose molecules can join together to form polymers

Polymer

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

Carbohydrates

A macromolecule that is broken down to glucose to provide energy.

Protein

A macromolecule polymer made of monomers of amino acids.

Lipids

Energy-rich organic macromolecules, such as fats, oils, and waxes, that are made of carbon, hydrogen, and oxygen.

nucleic acids

macromolecules containing hydrogen, oxygen, nitrogen, carbon, and phosphorus that make DNA and RNA

CHNOPS

A mnemonic for remembering the most common elements in all living things -Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulphur

cell membrane

A cell structure that controls which substances can enter or leave the cell.

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

Adhesion

An attraction between molecules of different substances

Cohesion

an attraction between molecules of the same substance

capillary action

the combined force of attraction among water molecules and with the molecules of surrounding materials

Transpiration

Evaporation of water from the leaves of a plant

Osmosis

Diffusion of water through a selectively permeable membrane

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Cellulase

enzyme that breaks down cellulose

Starch

A storage polysaccharide in plants consisting entirely of glucose.

Denature

A change in the shape of a protein (such as an enzyme) that can be caused by changes in temperature or pH (among other things).

Hydrolysis

Breaking down complex molecules by the chemical addition of water

dehydration synthesis

A chemical reaction in which two molecules are bonded together with the removal of a water molecule.

Lactase

an enzyme that catalyzes the hydrolysis of lactose to glucose and galactose.

null hypothesis

A prediction that there is no difference between groups or conditions, or a statement or an idea that can be falsified, or proved wrong.

activation energy

the minimum amount of energy required to start a chemical reaction

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Tonicity

The ability of a solution surrounding a cell to cause that cell to gain or lose water.

Hypotonic

This refers to a solution that, when surrounding a cell, will cause the cell to take up water.

Hypertonic

Having a higher concentration of solute than another solution.

Isotonic

Describes a solution whose solute concentration is equal to the solute concentration inside a cell

Trophisms

growth in response to an environmental stimulus

positive- towards stimulus

negative- away from stimulus

Phototropism

Growth of a plant shoot toward or away from light.

Chemotropism

the orientation of cells or organisms in relation to chemical stimuli; the growth or movement response of organisms to chemical stimuli

Thigmotropism

A directional growth of a plant in response to touch.

Geotropism/Gravitropism

response of a plant to the force of gravity; also called geotropism

taxis

Movement toward or away from a stimulus.

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Ribosome

Cytoplasmic organelles at which proteins are synthesized.

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Endoplasmic Reticulum (ER)

An extensive membranous network in eukaryotic cells, continuous with the outer nuclear membrane and composed of ribosome-studded (rough) and ribosome-free (smooth) regions.

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Vesicle

Small membrane-bound sac that functions in moving products into, out of, and within a cell.

Nucleus

A part of the cell containing DNA

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

DNA

deoxyribonucleic acid

DNA replication

The process in which DNA makes a duplicate copy of itself.

nitrogen base pairs

Adenine, Thymine, Guanine, Cytosine

Helicase

An enzyme that untwists the double helix of DNA at the replication forks.

Lagging strand

The strand in replication that is copied 3' to 5' as Okazaki fragments and then joined up.

Leading strand

The new continuous complementary DNA strand that is synthesised along the template strand in the mandatory 5' to 3' direction.

Transcription

(genetics) the organic process whereby the DNA sequence in a gene is copied into mRNA

Translation

Process by which mRNA is decoded and a protein is produced

Ribosome

Cytoplasmic organelles at which proteins are synthesized.

Watson and Crick

Developed the double helix model of DNA.

Rosalind Franklin

The scientist who generated x-ray images of DNA, she provided Watson and Crick with key data about DNA

Double Helix

two strands of nucleotides wound about each other; the structure of DNA