HBIO final

Lipid membrane structure

a continuous double layer of lipid molecules in which membrane proteins are embedded

Fluid Mosaic Model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Receptor Proteins

Proteins that transmit information in and out of cells. They allow communication between cells.

Selectively Permeable

a property of cell membranes that allows some substances to pass through, while others cannot

Diffusion

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

Concentration Gradient

difference in the concentration of a substance from one location to another

passive transport

the movement of substances across a cell membrane without the use of energy by the cell

hydrophobic

Water fearing

Hydrophilic

Attracted to water

Equilibrium

A state of balance, equal substance and water concentration in diffusion

Osmosis

the spontaneous net movement or diffusion of solvent molecules through a selectively-permeable membrane from a region of high water potential to a region of low water potential

Thermal energy

Heat energy

Tonicity

the ability of a surrounding solution to cause a cell to gain or lose water by osmosis

Isotonic

Having the same solute concentration as another solution. no net movement of molecules in or out

Hypertonic

external solution that has higher solute concentration and lower water concentration than inside fluids. Water moves in.

Hypotonic

External solution that has a lower solute concentration and a higher water concentration than inside fluids. Water moves out.

Active Transport

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

Facilitated diffusion

Movement of specific molecules across cell membranes through protein channels, regulates what moves in and out of cell

Aquaporin

protein that facilitates water transport across a plasma membrane through an aqueous pore

Exocytosis

a process by which the contents of a cell vacuole are released to the exterior through fusion of the vacuole membrane with the cell membrane.

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Receptor-mediated Endocytosis

The movement of specific molecules into a cell by the inward budding of membranous vesicles containing proteins with receptor sites specific to the molecules being taken in; enables a cell to acquire bulk quantities of specific substances.

Energy

the capacity to do work

kinetic energy

energy of motion

Potential Energy

stored energy that results from the position or shape of an object

Chemical Energy

A form of potential energy that is stored in chemical bonds between atoms.

Heat

thermal energy in transfer from one body of matter to another

Thermodynamics

The study of energy transformations that occur in a collection of matter.

Newtons 1st law

(Law of Inertia) an object in motion tends to stay in motion & an object at rest stays at rest unless acted upon by an outside force.

Newtons 2nd law

Force \= mass x acceleration

Entropy

a measure of the disorder of a system

Cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen, occurs in plants

Energy Conversion

A change from one form of energy to another

Exergonic Reaction

A chemical reaction that releases energy

Endergonic reaction

A chemical reaction that that absorbs free energy from its surroundings

Metabolism

the combination of chemical reactions through which an organism builds up or breaks down materials

Metabolic Pathway

A series of chemical reactions that either builds a complex molecule or breaks down a complex molecule into simpler compounds.

Energy Coupling

when energy produced in one reaction or system is used to drive another reaction or system

reactants

A starting material in a chemical reaction, undergoes change during reaction

Products

The elements or compounds produced by a chemical reaction.

Oxidative Phosphorylation

Production of ATP using the energy derived from the transfer of electrons in the ETC

Activation energy

the minimum amount of energy required to start a chemical reaction

activation energy barrier

Separates the energy levels of the reactants and products

Enzyme

biological catalyst, speeds up rate of chemical reaction in cells, most often a protein, can be used over and over

Substrate

substance on which an enzyme can act, enzymes bind substrates to their active sites

Active Site

a region on an enzyme that binds to a protein or other substance during a reaction.

Cofactors

nonprotein enzyme helpers

Coenzymes

vitamins that assist in the normal functioning of enzymes

Hydrolyzed

breaking down a compound with water (chemical reaction)

Glucose

the form of sugar that circulates in the blood and provides the major source of energy for body tissues. When its level is low, we feel hunger.

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

ADP

(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy

Calories

Units of heat that measure the energy used by the body and the energy that foods supply to the body

kilocalories

The measurement of energy in foods. Commonly referred to as calories.

Glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvic acid.

Citric Acid Cycle (Krebs)

Series of chemical reactions in aerobic respiration in which a acetyl coenzyme A is completely degraded to carbon dioxide and water with the release of metabolic energy that is used to produce ATP; also known as Kreb's cycle. Produces 2 ATP

Electron Transport Chain

A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP. produces 30-32 ATP

Chemiosmosis

process in which there is a production of adenosine triphosphate (ATP) in cellular metabolism by the involvement of a proton gradient across a membrane

NADH

the reduced form of NAD+; an electron-carrying molecule that functions in cellular respiration

FADH2

A molecule that stores energy for harvest by the electron transport chain.

Pyruvate

Organic compound with a backbone of three carbon atoms. Two molecules form as end products of glycolysis

pyruvate processing

pyruvate is oxidized to form acetyl CoA

Acetyl CoA

Acetyl coenzyme A; the entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme.

ATP synthase

Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP

Fermentation

Process by which cells release energy in the absence of oxygen, lactic acid and alcohol

Lactic Acid Fermentation

anaerobic chemical reaction, Lactic acid fermentation is a metabolic process by which glucose or other six-carbon sugars (also, disaccharides of six-carbon sugars, e.g. sucrose or lactose) are converted into cellular energy and the metabolite lactate, which is lactic acid in solution.

Alchohol Fermentation

A method of creating energy commonly used by eukaryotic bacteria like yeast in the absence of oxygen. Glucose undergoes glycolysis to create 2 ATP, 2 NADH and 2 pyruvate. The 2 pyruvate molecules are transformed into 2 Acetylaldehyde, releasing CO₂ in the process. Then NADH donates 2H+ and 2e- molecules to create 2 Ethanol.

Obligate Anaerobes

carry out fermentation or anaerobic respiration and cannot survive in the presence of O2

Facultative anaerobes

Can make enough ATP to survive using using fermentation or respiration, can survive with or without oxygen

Anaerobic respiration

Respiration that does not require oxygen

Aerobic respiration

Respiration that requires oxygen

How do we know Glycolysis is Ancient?

it does not require oxygen, which suggests that existed even when the atmosphere lacked oxygen.

Biosynthesis

The process by which living organisms produce larger molecules from smaller ones. multi-step, enzyme-catalyzed process where substrates are converted into more complex products in living organisms

Binary Fission

A form of asexual reproduction in single-celled organisms by which one cell divides into two cells of the same size

Chromosome

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

Chromatin

Clusters of DNA, RNA, and proteins in the nucleus of a cell

Cell division

the process in reproduction and growth by which a cell divides to form daughter cells

Interphase

Cell performing normal functions

S-phase

DNA replication occurs

Cytokinesis

division of a cell after mitosis or meiosis, split into two daughter cells

Mitosis

body cells, results in 2 identical cells to original

Meiosis

sex cells, results in 4 cells,

cleavage furrow

a shallow groove in the cell that indicates cytokinesis has begun

malignant tumors

irregular borders, grows quickly and can spread to other parts of the body

benign tumors

distinct, smooth borders, can become large but will not invade tissue or spread to other parts of body

cancer

uncontrolled cell growth, can be malignant or benign

heterzygous chromosomes

Chromosomes with differing gametes (Ex: Ee)

homozygous chromosomes

Chromosomes of the same letter/trait/gamete (Ex: CC)

gametes

sex cells (sperm and egg)

zygote

the fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo

autosome

Any chromosome that is not a sex chromosome

crossing over

Process in which homologous chromosomes exchange portions of their chromatids during meiosis.

random fertilization

source of genetic variation caused by the unlimited number of possible sperm & egg combinations

independent assortment

Independent segregation of genes during the formation of gametes

sister chromatid

one of two copies of the same genetic information

how many chromosomes do we have

46

redox reactions

oxidation-reduction reaction, chemical reaction that involves transfer of electrons between two organisms, they gain/lose an electron

Stomata

tiny openings on the epidermis of leaves, allow for gas exchange

How does Sexual reproduction benefit a species?

it creates genetic variation, which aids in evolution