Chapter 7

Front 1

Metabolism

Back 1

sum of all chemical reactions that occur in the body
can be divided into catabolic reactions and metabolic reactions

Front 2

Catabolic Reactions

Back 2

break down large chemicals and release energy

Front 3

Anabolic Reactions

Back 3

build up large chemicals and require energy

Front 4

Ingestion

Back 4

acquisition of food and other raw materials

Front 5

Digestion

Back 5

process of converting food into a usable soluble form so that it can pass through membranes in the digestive tract and enter the body

Front 6

Absorption

Back 6

passage of nutrient molecules through the lining of the digestive tract into the body proper. diffusion or active transport

Front 7

Transport

Back 7

circulation of essential compounds required to nourish the tissues and the removal of waste products from the tissues

Front 8

Assimilation

Back 8

building up of new tissues from digested food materials

Front 9

Respiration

Back 9

consumption of oxygen by the body; cells use oxygen to convert glucose into ATP

Front 10

Excretion

Back 10

removal of waste products produced during metabolic processes like respiration and assimilation

Front 11

synthesis

Back 11

creation of complex molecules from simple ones (anabolism)

Front 12

regulation

Back 12

control of physiological activities

Front 13

homeostasis

Back 13

body's metabolism functions to maintain its internal environment in a changing external environment

Front 14

irritability

Back 14

ability to respond to a stimulus and is part of regulation

Front 15

growth

Back 15

increase in size caused by synthesis of new materials

Front 16

photosynthesis

Back 16

process by which plants convert CO2 and H2O into carbs; sunlight is harnessed by chlorophyll to drive this reaction

Front 17

reproduction

Back 17

generation of additional individuals of a species

Front 18

protoplasm

Back 18

substance of life

Front 19

carbohydrates

Back 19

composed of carbon, hydrogen, and oxygen in a 1:2:1 ratio; storage forms of energy or as structural molecules

Front 20

monosaccharides

Back 20

fructose
glucose
galactose
mannose

Front 21

disaccharide

Back 21

composed of 2 monosaccharide subunits joined by dehydration synthesis
maltose and sucrose

Front 22

dehydration synthesis

Back 22

loss of a water molecule to make new molecules

Front 23

polysaccharides

Back 23

polymers of repeating monosaccharide subunits
glycogen, starch, and cellulose
insoluble in water

Front 24

hydrolysis

Back 24

by adding water, large polymers can be broken down into smaller subunits

Front 25

lipids

Back 25

composed of C, H, and O with much more H than O; do not form polymers; chief means of food storage in animals; provide insulation and protection against injury

Front 26

triglyceride

Back 26

type of lipid that consists of 3 fatty acid molecules bonded to a single glycerol backbone

Front 27

fatty acids

Back 27

have long carbon chains that give them their hydrophobic character and carboxylic acid groups that make them acidic; 3 dehydration reactions are needed to form 1 fat molecule

Front 28

phospholipid

Back 28

contain glycerol, 2 fatty acids, a phosphate group, and nitrogen-containing alcohol; lipid
e.g. lecithin & cephalin

Front 29

waxes

Back 29

esters of fatty acids and monohydroxylic alcohols; protective coating on skin, fur, leaves, and exoskeleton; lipid
e.g. lanolin

Front 30

steroids

Back 30

3 fused cyclohexane rings and 1 fused cyclopentane ring; lipid
cholesterol, sex hormones estrogen & testosterone & corticosteroids

Front 31

carotenoids

Back 31

fatty, acid-like carbon chains containing conjugated double bonds and carrying 6-membered carbon rings at each end; pigments that produce red, yellow, orange, and brown colors in plants and animals; lipid
carotenes & xanthophylls

Front 32

porphyrin

Back 32

contain 4 joined pyrrole rings; often complexed with metal; lipid
heme complexes with Fe in hemoglobin; chlorophyll is complexed with Mg

Front 33

proteins

Back 33

composed of C, H, O, N but may also contain P and S; polymers of amino acids

Front 34

peptide bonds

Back 34

bond that joins amino acids through dehydration reactions; chains of these bonds produce polypeptides

Front 35

primary structure

Back 35

sequence of amino acids

Front 36

secondary structure

Back 36

based on hydrogen-bonding between adjacent amino acids and results in beta pleated sheets or alpha helices

Front 37

tertiary structure

Back 37

3-D structure that is based on R-group interactions between adjacent amino acids; results in globular or fibrous proteins; hydrophobic amino acids are crowded in the center with hydrophilic amino acids at the outer edge and periphery

Front 38

quaternary

Back 38

interaction and joining of 2 or more independent polypeptide chains

Front 39

simple protein

Back 39

composed entirely of amino acids

Front 40

albumins and globulin

Back 40

these are primarily globular in nature; functional proteins that act as carriers or enzymes

Front 41

scleroproteins

Back 41

fibrous in nature & act as structural proteins
collagen

Front 42

conjugated proteins

Back 42

contain a simple protein portion plus at least one nonprotein fraction

Front 43

lipoproteins

Back 43

proteins bound to lipids

Front 44

glycoproteins

Back 44

proteins bounds to carbs

Front 45

chromoproteins

Back 45

proteins bound to pigmented molecules

Front 46

metalloproteins

Back 46

proteins complexed around a metal ion

Front 47

nucleoproteins

Back 47

proteins containing histone or protamine (nuclear protein) bound to nucleic acids

Front 48

protein functions

Back 48

1. hormones
2. enzymes
3. structural proteins
4. transport proteins
5. antibodies

Front 49

hormones

Back 49

proteins that function as chemical messengers secreted into the circulation
insulin & ACTH

Front 50

enzymes

Back 50

biological catalysts that act by increasing the rate of chemical reactions important for biological functions
amylase, lipase, ATPase

Front 51

structural proteins

Back 51

contribute to the physical support of a cell or tissue; may be extracellular (collagen) or intracellular (proteins in cell membranes)

Front 52

transport proteins

Back 52

carriers of important materials
hemoglobin carries oxygen in circulation, cytochromes carry electrons during cellular respiration

Front 53

antibodies

Back 53

proteins that bind to foreign particles (antigens), including disease-causing organisms, that have entered the body

Front 54

catalyst

Back 54

any substance that affects the rate of a chemical reaction without itself being changed

Front 55

substrate

Back 55

molecule upon which an enzyme acts

Front 56

active site

Back 56

area on each enzyme to which the substrate binds

Front 57

when concentrations of both enzymes and substrate are low...

Back 57

many of the active sites on the enzyme are unoccupied and the reaction rate is low

Front 58

increasing substrate concentration will...

Back 58

increase reaction rate until all of the active sites are occupied

Front 59

competitive inhibition

Back 59

if a similar molecule is present in a concentration comparable to the concentration of the substrate, it will compete with the substrate for binding sites on the enzyme and interfere with enzyme activity
enzyme is inhibited by the inactive substrate/competitor

Front 60

noncompetitive inhibitor

Back 60

substance that forms strong covalent bonds with an enzyme and consequently may not be displaced by the addition of excess substrate; irreversible; may be bound at, near, or remote from the active site

Front 61

allosteric inhibition

Back 61

noncompetitive inhibition; when inhibition takes places at a site other than the active site; interaction of an inhibitor at an allosteric site changes the structure of the enzymes so that the active site is also changed

Front 62

lactase

Back 62

hydrolyzes lactose to the monosaccharides glucose and galactose

Front 63

proteases

Back 63

degrade proteins to amino acids

Front 64

lipases

Back 64

break down lipids to fatty acids and glycerol

Front 65

cofactors

Back 65

nonprotein molecules required by many enzymes to become active; can be metal cations or small organic groups called coenzymes

Front 66

prosthetic groups

Back 66

cofactors that bind to the enzymes by strong covalent bonds

Front 67

cell theory

Back 67

1. all living things are composed of cells
2. cell is the basic functional unit of life
3. chemical reactions of life take place inside cell
4. cells arise only from pre-existing cells
cells carry genetic info in the form of DNA; this genetic material is passed from parent to daughter cell

Front 68

cell membrane

Back 68

encloses the cell & exhibits selective permeability; regulates passage of materials into and out of the cell; fluid mosaic model; consists of phospholipid bilayer with proteins embedded throughout

Front 69

passage through cell membrane

Back 69

readily permeable to both small, nonpolar hydrophobic molecules (oxygen) and small polar molecules
small charged particles cross through protein channels
charged ions & larger charged molecules cross the membrane with assistance of carrier proteins

Front 70

nucleus

Back 70

controls activities of cell, including cell division; surrounded by nuclear membrane; contains DNA which is complexed with structural proteins called histones to form chromosomes

Front 71

nucleolus

Back 71

dense structure in nucleus where ribosomal RNA (rRNA) synthesis occurs

Front 72

ribosome

Back 72

sites of protein production & are synthesized by the nucleolus; free ribosomes are found in cytoplasm & bound ribosomes line the outer membrane of the endoplasmic reticulum

Front 73

endoplasmic reticulum

Back 73

network of membrane enclosed spaces involved in transport of materials throughout the cell, particularly those materials destined to be secreted by the cell

Front 74

golgi apparatus

Back 74

receives vesicles & their contents from smooth ER, modifies them, repackages them into vesicles & distributes them to cell surface by exocytosis

Front 75

mitochondria

Back 75

sites of aerobic respiration within cell & suppliers of energy; composed of outer & inner phospholipid bilayer

Front 76

cytoplasm

Back 76

where most of cell's metabolic activity occurs; transport occurs by cyclosis

Front 77

cyclosis

Back 77

streaming movement within the cell

Front 78

vaculoes/vesicles

Back 78

membrane-bound sacs involved in transport & storage of materials that are ingested, secreted, processed, or digested by the cell

Front 79

centrioles

Back 79

involved in spindle organization during cell division & are not bound by a membrane; animal cells have a pair that are oriented at right angles to each other and lie in a region called centrosome; plant cells don't have them

Front 80

lysosomes

Back 80

membrane-bound vesicles that contain hydrolytic enzymes involved in intracellular digestion; break down material ingested by the cell

Front 81

autolysis

Back 81

an injured or dying tissue may commit suicide by rupturing the lysosome membrane and releasing its hydrolytic enzymes

Front 82

cytoskeleton

Back 82

supports the cell, maintains its shape, and functions in cell motility; composed of microtubules, microfilaments, and intermediate filaments

Front 83

microtubules

Back 83

hollow rods made of tubulin that radiate throughout the cell and provide it with support
centrioles, cilia, and flagella

Front 84

microfilaments

Back 84

solid rods of actin, which are important in cell movement & support
muscle contraction

Front 85

plant cells

Back 85

1. no centrosome
2. presence of cell wall composed of cellulose
3. chloroplasts in many cells of green plants are sites of synthesis of organic compounds (photosynthesis)
4. no lysosomes
5. many vacuoles/mature plant cells usually contain one large vacuole

Front 86

simple diffusion

Back 86

net movement of dissolved particles down their concentration gradients from a region of higher concentration to a region of lower concentration; passive; requires no external source of energy

Front 87

osmosis

Back 87

simple diffusion of water from a region of lower solute concentration to a region of higher solute concentration

Front 88

hypertonic

Back 88

when cytoplasm of a cell has lower solute concentration than the extracellular medium, medium is...
water will flow out of cell
plasmolysis
will cause cell to shrivel

Front 89

hypotonic

Back 89

extracellular environment is less concentrated than cytoplasm of cell, extracellular medium is...
water will flow into cell
will cause cell to burst
lyse

Front 90

facilitated diffusion

Back 90

passive transport; net movement of dissolved particles down their concentration gradient through special channels or carrier proteins in the cell membrane; does not require energy

Front 91

active transport

Back 91

net movement of dissolved particles against their concentration gradient with the help of transport proteins; requires energy

Front 92

energy independent carriers

Back 92

facilitate movement of compounds along a concentration gradient

Front 93

symporters

Back 93

move 2 or more ions or molecules

Front 94

antiporters

Back 94

exchange one or more ions or molecules for another ion or molecule

Front 95

pump

Back 95

energy-dependent carriers (require ATP)
sodium-potassium pump

Front 96

endocytosis

Back 96

process in which the cell membrane invaginates, forming a vesicle that contains extracellular medium

Front 97

pinocytosis

Back 97

endocytosis; ingestion of fluids or small particles

Front 98

phagocytosis

Back 98

endocytosis; engulfing of large particles; particles may bind to receptors on cell membrane before being engulfed

Front 99

exocytosis

Back 99

vesicle within the cell fuses with the cell membrane and releases its contents to the outside

Front 100

brownian movement

Back 100

kinetic energy spreads small suspended particles throughout the cytoplasm of the cell