AP Bio Units 1-4 Review Diagram | Quizlet

RNA

ribonucleic acid; single-stranded nucleic acid that contains the sugar ribose

nucleotide

monomer of nucleic acids made up of a 5-carbon sugar, a phosphate group, and a nitrogenous base

deoxyribose

A five-carbon sugar that is a component of DNA nucleotides; contains one less oxygen that the five-carbon sugar in RNA nucleotides

ribose

A five-carbon sugar that is a component of RNA nucleotides

purine

double-ring nitrogenous base; adenine and guanine

pyrimidine

single-ring nitrogenous base; thymine, cytosine, or uracil (CUT)

adenine

The base that pairs with thymine in DNA and with uracil in RNA

thymine

the nucleotide that hydrogen bonds with adenine in DNA.

guanine

The base that pairs with cytosine in DNA and RNA

uracil

The base found in RNA (but not in DNA) that base pairs with adenine

cell signaling

The process of cell-to-cell communication mediated by signaling molecules and membrane receptors. Composed of three steps:

1) reception

2) transduciton

3) response

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells; another term for cell membrane

polar

Molecule with partial charges. Mixes with water.

nonpolar

No partial charges. Do not mix with water.

intracellular receptor

receptors located inside the cell rather than on its cell membrane; activated by membrane-permeable ligands such as steroid hormones

steroid hormone

Nonpolar, lipid hormones that activate intracellular receptors; testosterone and estrogen are examples

receptor

protein that detects a signal molecule and performs an action in response

ligand

A molecule that binds specifically to a receptor site of another molecule.

apoptosis

programmed cell death involving a cascade of specific cellular events leading to death and destruction of the cell

negative feedback

A primary mechanism of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

positive feedback

A physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change.

sodium-potassium pump

A transport protein in the plasma membrane of animal cells that actively transports sodium out of the cell and potassium into the cell. Important for establishing the resting potential of neurons. Also called Na+/K+-ATPase

membrane potential

the voltage (charge) difference across a membrane

electrochemical gradient

The diffusion gradient of an ion, which is affected by both the concentration difference of an ion across a membrane (a chemical force) and the ion's tendency to move relative to the membrane potential (an electrical force).

null hypothesis

the hypothesis that there is no significant difference between specified populations, any observed difference being due to sampling or experimental error.

tertiary protein structure

three-dimensional folding pattern of a protein due to interactions between amino acid R-groups

ionic bond

A chemical bond resulting from the attraction between oppositely charged ions.

reception

The target cell's detection of a signal molecule coming from outside the cell.

transduction

the signaling molecules binds to the receptor and changes it shape, causing the receptor to change its function

response

In cellular communication, the change in a specific cellular activity brought about by a transduced signal from outside the cell.

phosphate group

A chemical group consisting of a phosphorus atom bonded to four oxygen atoms; has a negative charge

phosphorylation

The transfer of a phosphate group, usually from ATP, to a molecule.

kinase

An enzyme that adds a phosphate group to a molecule

phosphatase

An enzyme that removes a phosphate group from another molecule.

G protein-coupled receptors (GPCRs)

a large family of proteins that function as receptors; they provide a mechanism for molecules outside a cell to influence the inner workings of the cell.

Signaling cascade

Series of events, starting with the binding of a ligand to a receptor. This sequence of events ultimately results in a change in cellular behavior

second messenger

a molecule that is generated when a specific substance attaches to a receptor on the outside of a cell membrane, which produces a change in cellular function

cAMP

a second messenger produced in GPCR signaling

ligand-gated ion channel

Type of membrane receptor that has a region that can act as a "gate" when the receptor changes shape. When the receptors are activated they open and allow ions to cross the cell membrane.

receptor tyrosine kinase

A cell surface receptor that also has kinase activity; when these receptors are activated they stimulate phosphorylation cascades

phosphorylation cascade

a sequence of events where one enzyme phosphorylates another, causing a chain reaction leading to the phosphorylation of many proteins

photosynthesis

Process by which autotrophs produce glucose using energy from the sun and CO2

chemical reaction for photosynthesis

6CO2 (carbon dioxide) + 6H2O (water) +energy -->

C6H12O6 (glucose) + 6O2 (oxygen)

cellular respiration

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

chemical reaction for respiration

C6H12O6 (glucose) + 6O2 (oxygen) -->

6CO2 (carbon dioxide) + 6H2O (water) + ATP (energy)

Steps of photosynthesis

1. Light-dependent reactions

2. Calvin cycle

light-dependent reactions

First step of photosynthesis; uses energy from light to produce ATP and NADPH

Calvin Cycle

Second step in photosynthesis; uses ATP and NADPH (from light reactions) and CO2 to build organic molecules such as glucose

outputs of light-dependent reaction

O2, ATP, and NADPH

inputs of light-dependent reaction

Light (photons), water, NADP+, and ADP+Pi

inputs of Calvin cycle

ATP, NADPH, and CO2

outputs of Calvin cycle

Glucose, ADP, and NADP+

rubisco

The most abundant protein on earth. Performs carbon fixation in the Calvin Cycle.

carbon fixation

The initial incorporation of carbon into organic compounds.

ATP synthase

Large protein that uses energy from H+ ions diffusing down their concentration gradient to bind ADP and a phosphate group together to produce ATP

chlorophyll

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

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.

NADPH

An electron carrier involved in photosynthesis. Light drives electrons from chlorophyll to NADP+, forming NADPH, which provides the high-energy electrons for the reduction of carbon dioxide to sugar in the Calvin cycle.

photon

a particle of light

H+

hydrogen ion (proton)

TERM

thylakoid

DEFINITION

A flattened membrane sac inside the chloroplast, used to convert light energy into chemical energy.

TERM

granum

DEFINITION

A stack of thylakoids in a chloroplast

TERM

stroma

DEFINITION

fluid portion of the chloroplast; outside of the thylakoids

TERM

intermembrane space

DEFINITION

narrow region between the inner and outer membranes

proton pump

An electrogenic pump that moves H+ ions into the thylakoid lumen; powered the electron transport chain.

TERM

inner membrane

DEFINITION

The membrane of the mitochondria that is the site of electron transport and chemiosmosis.

matrix

Innermost compartment of the mitochondrion

glycolysis

the breakdown of glucose by enzymes, releasing energy and pyruvate

aerobic respiration

requires oxygen; occurs in the cytosol and mitochondria

anaerobic respiration

Respiration that does not require oxygen; occurs in the cytosol

fermentation

A process that replenishes NAD+ to be used in glycolysis, so that ATP can be made via anaerobic respiration; produces a characteristic end product, such as ethanol (alcohol) or lactic acid.

NADH

An energy-carrying coenzyme produced by glycolysis and the Krebs cycle. NADH carries energy to the electron transport chain, where it is stored in ATP.

electron carrier

a compound that can accept a pair of high-energy electrons and transfer them, along with most of their energy, to another molecule

FADH2

electron carrier produced during the Krebs cycle

Krebs Cycle

second stage of cellular respiration, in which pyruvic acid (pyruvate) is broken down into carbon dioxide in a series of energy-extracting reactions; also known as The Citric Acid (TCA) Cycle

oxidative phosphorylation

The production of ATP using energy derived from the redox reactions of an electron transport chain; the final stage of aerobic cellular respiration.

endergonic

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

exergonic

a chemical reaction that releases energy

cristae

Infoldings of the inner membrane of a mitochondrion that houses the electon transport chain and the enzyme catalyzing the synthesis of ATP.

H+ gradient

proton motive force that drives the ATP synthase to make ATP

electron acceptor

A reactant that gains an electron and is reduced in a reduction-oxidation reaction. Oxygen in respiration and NADP+ is photosynthesis.

metabolism

All of the chemical reactions that occur within an organism

anabolism

Metabolic pathways that build larger molecules

catabolism

Metabolic pathways that break down molecules

activation energy

Energy needed to start a chemical reaction

catalyst

substance that speeds up the rate of a chemical reaction

ATP

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

ADP

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

peptide bond

covalent bond formed between amino acids

enzyme

protein that speeds up a chemical reaction (catalyst)

active site

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

substrate

reactant of an enzyme-catalyzed reaction

competitive inhibition

substance that resembles the normal substrate competes with the substrate for the active site

noncompetitive inhibitor

A substance that reduces the activity of an enzyme by binding to a location remote from the active site, changing the enzymes shape so that it can no longer catalyze a chemical reaction

endosymbiosis

The theory that mitochondria and chloroplasts were once independent prokaryotes that were engulfed (phagocytosis) by another much larger cell.

endosybiosis: evidence in support

Chloroplasts and mitochondria have:

1- double membranes

2- their own DNA

3- their own ribosomes

eukaryote

A cell that contains a nucleus and membrane bound organelles

phospholipid

A lipid containing a polar phosphate head and nonpolar fatty acid tails

phospholipid bilayer

A double layer of phospholipids that makes up cell and organelle membranes.

glycoprotein

A protein with one or more covalently attached carbohydrates. Important in cell-to-cell communication.