Test 2 (Chapters 5,6,7) | BIOL 1001 - GENERAL BIOLOGY, Quizzes of Biology

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Plasma Membrane Functions

The plasma membrane contains the cells but still allows the cell the interact with theenvironmentalFunctions:1. isolate the cellenvironment2. regulate exchange between inside and outside3. communicate with other cells4. identify the cell type TERM 2

Plasma Membrane

DEFINITION 2 the membrane at the boundary of every cell that acts as a selective barrier,therebyregulating the cells chemical enviroment TERM 3

Fluidity

DEFINITION 3 there is a lateral two-dimensionalmovement of the lipids and some proteins in the plane of the membrane TERM 4

Mosaic Aspect of Membranes

DEFINITION 4 there are proteinsinterspersedwithin the lipid bilayer TERM 5

Functions of Membrane Proteins

DEFINITION 5

1. transport proteins- channel proteins: pores, carrier proteins: selective revolving doors2. receptors3. cell-to-cell recognition

Glycoproteins

proteins which have a carbohydrate attached to them TERM 7

Passive Transport

DEFINITION 7 Movement down a concentration gradient, movement from greater concentration to lower concentrartion TERM 8

Concentration Gradient

DEFINITION 8 a concentration change over a distance in a particular direction TERM 9

Diffusion

DEFINITION 9 the net movement of a substance down a concentration gradient TERM 10

Selective

Permeability

DEFINITION 10 the property of biologicalmembraneswhich allows some substances to cross more easily than others

Aquaporins

Water is able to enter and exit the cell through specialized protein channels called _____ TERM 12

Facilitated Diffusion

DEFINITION 12 Diffusion across a membrane with the help of a protein. types:1. bind and release2. selective channel, a pore the size of the solute3. gated channel TERM 13

Osmosis

DEFINITION 13 the diffusion of water across adeferentiallypermeable membrane.The tendency of water to move through a membrane from an area of lower concentration into an area of higher concentration solution, dilution it, until there is equal concentrations of fluid on both sides of the membrane TERM 14

Isotonic

DEFINITION 14 a solution of equal concentration to another solution TERM 15

Hypertonic

DEFINITION 15 a solution with a greater concentration of solute than another solutionwater leaves the cell, causing it to shrivel

Hypotonic

a solution with a lowerconcentrationof solute than another solutionwater rushes into the cell, causing it to swell TERM 17

Active Transport

DEFINITION 17 anenergyrequiring process during which a transport protein pumps a molecule across a membrane against its concentration gradient-energyrequiring-uses ATP-used to maintain ion gradients TERM 18

Endocytosis

DEFINITION 18 the cellular uptake of large molecules and particulate substances (food) by the localized pinching off of a region of the plasma membrane to form a vesicle types:phagocytosispinocytosisreceptor-mediated endocytosis TERM 19

Phagocytosis

DEFINITION 19 (cell eating) the endocytosis of solid particles. TERM 20

Pinocytosis

DEFINITION 20 (cell drinking) is the endocytosis of fluid droplets

Receptor-mediated endocytosis

the process of importing specificmacro moleculesinto the cell by the inward budding ofvesiclesformed from coated pits, occurs in response to the binding of specificnutrientsto receptors on the cells surface TERM 22

Exocytosis

DEFINITION 22 the cellular secretion of large molecules by the fusion of vesicles with the plasma membrane. moves the material out of the cell TERM 23

desmosomes

DEFINITION 23 cells are connected by this structure in which protein filaments hold cells together TERM 24

tight

junctions

DEFINITION 24 if the connection between cells needs to be watertight then cells are held together by this structure in which proteins seal cells together TERM 25

Gap Junctions

DEFINITION 25 (animal cells communicate) two channel proteins in adjacent cells line up

Communication between cells

gap junctions and plasmodesmata TERM 27

Plasmodesmata

DEFINITION 27 (plant cells) large non-protein channels through both the cellmembranesand the cell wall of neighboring plant cells TERM 28

matter

DEFINITION 28 anything that takes up space and has mass-the physical material of the universe TERM 29

energy

DEFINITION 29 the capacity to do workTwo major categories of energy:1.potential energy2. kinetic energy TERM 30

potential energy

DEFINITION 30 energy stored in matter because of its position or location

kinetic energy

the energy of motion TERM 32

first law of thermodynamics

DEFINITION 32 energy can be transferred and transformed, but it cannot be created or destroyed TERM 33

second law of thermodynamics

DEFINITION 33 every energy transfer or transformation makes the universe more disordered TERM 34

entropy

DEFINITION 34 the measure of disorder, randomness TERM 35

closed system

DEFINITION 35 a system which is completely isolated from its surroundings

open system

energy can be transferred between the system and the surroundings TERM 37

exergonic reactions

DEFINITION 37 -releases energy-reaction is energetically downhill- spontaneous reactionex- burning glucose TERM 38

endergonic

DEFINITION 38 -requires energy-reaction is energetically uphill-non- spontaneous reaction (Requires energy source)ex- photosynthesis TERM 39

activation energy

DEFINITION 39 the amount of energy that reactant molecules must absorb to start a reaction TERM 40

metabolism

DEFINITION 40 the total of an organisms chemical processes-uptake of matter and energy-conversion to usable form-synthesis of cellular materials-elimination of waste products

metabolic pathways

organizes chemistry of life2 Types:1. catabolic pathways2. anabolic pathways TERM 42

catabolic pathways

DEFINITION 42 metabolic pathways which release energy by breaking down complex molecules to simpler compounds-degradation, release energy TERM 43

anabolic pathway

DEFINITION 43 metabolic pathways which consume energy to build complicated molecules from simpler ones-synthesis, energy requiring TERM 44

catalysts

DEFINITION 44 chemical agents that accelerate a reaction without beingpermanentlychanged in the process (a catalyst is reusable and not destroyed by reaction) TERM 45

enzymes

DEFINITION 45 (lock) biological catalysts which are usually proteins- substrate-specific

substrates

(key) the substances which enzymes act on TERM 47

active site

DEFINITION 47 (key hole) the restricted region of an enzyme molecule where the substrate is bound TERM 48

coenzymes

DEFINITION 48 small non-protein organic molecules that are required for proper enzyme catalysis TERM 49

feedback inhibition

DEFINITION 49 the regulation of a metabolic pathway by its end product, which inhibits an enzyme at an earlier point in the pathway TERM 50

allosteric sites

DEFINITION 50 specific receptor sites on some part of the enzyme molecules other than the active site

competitive inhibitors

chemicals that resemble a enzyme's normal substrate and compete with it for the active site-block the active site by binding but not reacting-reversible TERM 52

photosynthesis

DEFINITION 52 transforms light energy trapped by chloroplasts into chemical bond energy and stores that energy in sugar and other organic molecules-synthesis of energy rich organic molecules (glucose) from energy poor molecules-uses CO2 as a carbon source and sunlight energy as the energy source- directly or indirectly supplies energy to most living organisms TERM 53

chlorophyll

DEFINITION 53 the green pigment that gives a leaf its color. chlorophyll is also responsible for the absorption of the light energy that drives photosynthesislocated in cells of mesophyll (interior of the leaf) TERM 54

stomata or stoma

DEFINITION 54 leaf pores where CO2 and H2O enter TERM 55

vascular bundle

DEFINITION 55 where water is absorbed and transported to leaves

thylakoids

flattened membranous sacs inside the chloroplast TERM 57

2 reactions of photosynthesis

DEFINITION 57 1 light-dependent reaction2 light-independent reaction TERM 58

light-dependent reaction

DEFINITION 58 -sunlight is converted into chemical energy that is stored in energy-carrier molecules called ATP and NADPH-oxygen is released as a by-product-occurs in thylakoid membranes TERM 59

light-independent reactions

DEFINITION 59 -the chemical energy in the carrier molecules (ATP and NADPH) is used to make glucose, and other organic molecules-takes place in the stroma, the fluid-filled space outside the thylaoids within the chloroplast TERM 60

nature of sunlight

DEFINITION 60 -light is electromagnetic energy-has both wavelike and particle like properties

wavelike properties

shorter wavelength light has higher energy, while longer wavelength light has lower energyelectromagnetic spectrum TERM 62

visible

light

DEFINITION 62 400nm to 750nm TERM 63

electromagnetic spectrum

DEFINITION 63 gamma rays (10^-3 nm) - radio waves (10^3 nm) TERM 64

particle like properties

DEFINITION 64 electromagnetic energy travels in discrete particles called photons TERM 65

pigments

DEFINITION 65 substances that absorb visible light

chlorophyll

the pigment which is the key light-capturing molecule in thylakoid membranes TERM 67

accessory pigments

DEFINITION 67 carotenoids and phycocyanins TERM 68

photosystems

DEFINITION 68 the assemblies which turn light energy into chemical energy in the thylakoid membranes-chlorophyll, proteins, and the accessory pigments are arranged int a photsystem TERM 69

chemiosmosis

DEFINITION 69 the coupling of electron flow down an electron transport chain t ATP production by creation of gradient across the membrane.the proton gradient drives ATP synthesis as proteins diffuse back across the membrane TERM 70

calvin-benson cycle

DEFINITION 70 the cycle of reactions in photosynthesis in which atmospheric carbo CO2 is fixed using ATP and NADPH- occurs in the chloroplast stroma-no direct light energy required-NADPH and ATP provide chemical energyThree phases:1. carbon fixation2. G3P synthesis (atp is used, nadph is used)3. RuBP- sugar carbons are shuffled around to make 3 5-carbon sugars from 5 3-carbon sugars

carbon fization

acquiring carbon from the atmosphere and incorporating it into a larger organicmolecule.