BIOL 1306 Exam 3 Vocab

Free energy

energy that is available to do work

Exergonic

reaction where energy is released, spontaneous

Endergonic

energy required, non spontaneous

Catabolism

reactions that split covalent bonds

Anabolism

building larger molecules from smaller molecules

Activation energy

energy required to destabilize bonds in reactants

Active site

region of the enzyme that interacts with substrate

Substrate

reactant specific for a particular enzyme

Catalyst

decreases EA activation energy, not consumed during reaction

Enzyme activity

rate at which enzyme converts substrates product(s)

Competitive inhibitor

attach to active site and block substrate from entering

Allosteric inhibitor

changes shape of enzyme so it cannot bind to substrate

Interphase

most of the cells life

Mitosis

division of chromosomes

Cytokinesis

division of the cytoplasm

Centrosome

point of origin for microtubules , made up of two centrioles

Centromere

DNA sequence on each chromosome where sister chromatids are closely attached

Chromosome

1 double stranded molecule of DNA wound around histone proteins

Chromatid

identical copy of a chromosome

Prophase

first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus

Spindle fiber

array of microtubules that emerge from centrioles, attach to chromosomes to pull them apart during mitosis

Centriole

Organize microtubules and arrange nucleus

Prometaphase

The second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes.

Kinetochore

protein structure that links centromere to spindle fiber

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

sister chromatids separate

Telophase

nuclear envelope reforms, making 2 nuclei

Cleavage furrow

The area of the cell membrane that pinches in and eventually separates the dividing cell

Adaptation

heritable characteristics that enhance survival and/or reproduction

acclimitization

change within an individual in response to short-term changes in the environment

conformer

allows its internal condition to vary with certain external changes

regulator

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

Homeostasis

maintaining a predictable internal environment

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.

ectotherm

source of body heat comes from the external environment

endotherm

source of body heat comes from internal metabolism

convection

heat transfer by the movement of a fluid

conduction

heat transfer between objects in direct contact

radiation

any object warmer that 0 kelvin

evaporation

liquid molecules with highest kinetic energy escape into gas phase

osmolarity

total concentration of all solute particles in a solution

hypoosmotic

solution with a lesser concentration of solute

hyperosmotic

solution with a greater concentration of solute

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

major nitrogenous waste excreted in urine, high water solubility

uric acid

nitrogenous waste excreted in the urine, low water solubility

hemolymph

circulatory fluid

interstitial fluid

fluid between cells

erythrocyte

red blood cell

leukocyte

white blood cell

transpiration

evaporation of water our of stomata in leaves

xylem

vessels that move water and ions one-way from roots to leaves

phloem

vessels that move sugars and macromolecules and upanddownhormones

tracheid

long thin tubes with perforated with secondary cell walls

vessel element

type of xylem cell that forms part of a continuous tube through which water can move

sieve tube element

cells consisting of cytoplasm and cell membrane, no nucleus

companion cell

have nucleus and organelles, cell membrane connected to sieve tube elements by plasmodesmata

plasmodesmata

channels of cytoplasm connecting plant cells

water potential

The physical property predicting the direction in which water will flow, governed by solute concentration and applied pressure.

solute potential

This measurement has a maximum value of 0; it decreases as the concentration of a solute increases.

pressure potential

A component of water potential that consists of the physical pressure on a solution, which can be positive, zero, or negative.

cohesion

hydrogen bonds between like molecules

adhesion

hydrogen bonds between 2 different molecules

primary cell wall

In plants, a relatively thin and flexible layer that surrounds the plasma membrane of a young cell.

secondary cell wall

In plant cells, a strong and durable matrix that is often deposited in several laminated layers around the plasma membrane and provides protection and support.

ligand

Any molecule that bonds specifically to a receptor site of another molecule.

hormone

Chemical messengers, mostly those manufactured by the endocrine glands, that are produced in one tissue and affect another

paracrine

of or relating to a hormone or to a secretion released by endocrine cells

endocrine

the body's "slow" chemical communication system; a set of glands that secrete hormones into the bloodstream

pheromone

A chemical released by one animal that affects the behavior of another animal of the same species.

second messenger

A small, nonprotein, water-soluble molecule or ion, such as calcium ion or cyclic AMP, that relays a signal to a cell's interior in response to a signal received by a signal receptor protein.

kinase

an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule.

gene transcription

the process of making a copy of genetic information stored in a DNA strand into a complementary strand of RNA

cholecystokinin

a hormone that is secreted by cells in the duodenum and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas.

secretin

a hormone released into the bloodstream by the duodenum (especially in response to acidity) to stimulate secretion by the liver and pancreas.

gastrin

hormone secreted in the stomach that stimulates secretion of HCl and increases gastric motility

G1 phase

The first gap, or growth phase, of the cell cycle, consisting of growth, making organelles and proteins.

G2 phase

The second growth phase of the cell cycle, consisting of continued growth and preparation for cell division

S phase

chromosomes are copied to prepare for cell division