biol 1306 exam 3

chromosome

one double-stranded molecule of DNA would around histone proteins

chromatin

all chromosomes in the nucleus

interphase

most of the cells life

G1

cell grows, organelles duplicate

S

synthesis of DNA; chromosomes are copied to prepare for cell division

G2

Final preparation phase. Cell checks for DNA errors and begins to form centrosomes. (Prepares for Mitosis)

mitosis

part of eukaryotic cell division during which the cell nucleus divides

cytokinesis

division of the cytoplasm

centrosome

A structure in animal cells containing centrioles from which the spindle fibers (microtubules) develop.

sister chromatids

identical copies of a chromosome joined together in the center by a centromere and held by cohesin

centromere

DNA sequence where sister chromatids are closely attached

spindle

fanlike microtubule structure that helps separate the chromosomes during mitosis

kinetochore

A structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle.

adaptation

heritable characteristic that enhances survival to reproduce

acclimatization

short term change in an individuals physiology in response to change in the environment

homeostasis

maintaining a predictable internal environment

stimulus

a signal to which a variable respond s

sensor

tissue that detects value of a variable

control center

read sensor value and initiates response

response

tissue does something that increases or decreases the variable

endotherm

An organism that is internally warmed by a heat-generating metabolic process

exotherm

organism that absorbs its body heat from the environment

conformity

internal environment matches external value of a variable

regulation

animal spends energy to maintain internal variable the same over wide range of external conditions

partial regulation

maintaining an internal variable at stable level OR animal maintains internal conditions slightly above external

conduction

The direct transfer of heat from one substance to another substance that it is touching.

convection

The transfer of thermal energy by the circulation or movement of a liquid or gas

radiation

Energy that is radiated or transmitted in the form of rays or waves or particles.

evaporation

liquid molecules with the highest kinetic energy escape to a gas phase

interstitial fluid

fluid between cells

hemolymph

the fluid that circulates through the body of an animal that has an open circulatory system

erythrocytes

red blood cells, carry oxygen

leukocytes

white blood cells, fight infection

endothelial cells

The thin layer of cells that line the interior surface of all blood vessels. Only one cell thick in capillaries.

bulk flow

the movement of a fluid driven by pressure

hormones

chemical signals produced by endocrine cells

endocrine cells

secrete hormones into interstitial fluid and capillaries

plasmodesmata

An open channel in the cell wall of plants through which strands of cytosol connect from adjacent cells

paracrine

Referring to a secreted molecule that acts on a neighboring cell.

pheromones

odorless chemicals that serve as social signals to members of one's species

hypoosmotic

lower solute concentration, cell bursts

hyperosmotic

higher solute concentration, cell shrinks

isosmotic

solutions with the same concentrations of solute particles

ammonia

A small, very toxic molecule (NH3) produced by nitrogen fixation or as a metabolic waste product of protein and nucleic acid metabolism.

urea

waste product formed in the liver, filtered out of the blood by the kidneys, and excreted in urine by mammals

uric acid

nitrogenous waste excreted as a paste which helps organism conserve water

cleavage furrow

the first sign of cytokinesis during cell division in an animal cell; a shallow groove in the cell surface near the old metaphase plate

free energy

energy that is available to do work

endergonic

A chemical reaction that requires the input of energy in order to proceed.

exergonic

Chemical reactions that release energy

catabolism

Metabolic pathways that break down molecules, releasing energy.

anabolism

Metabolic pathways that construct molecules, requiring energy.

activation energy

Energy needed to get a reaction started

active site

The part of an enzyme or antibody where the chemical reaction occurs.

substrate

A specific reactant acted upon by an enzyme

catalyst

substance that speeds up the rate of a chemical reaction and remains unchanged

enzyme activity

Rate at which an enzyme catalyzes a reaction.

allosteric inhibitor

binds to allosteric site and reduces enzyme activity

competitive inhibitor

A substance that reduces the activity of an enzyme by entering the active site in place of the substrate whose structure it mimics.

insulin

A protein hormone synthesized in the pancreas that regulates blood sugar levels by facilitating the uptake of glucose into tissues

glucagon

A protein hormone secreted by pancreatic endocrine cells that raises blood glucose levels; an antagonistic hormone to insulin.