As Biology Unit 1 Module 2

Front 1

The net movement of molecules or ions in a gas or liquid from an area of high concentration to an area where they are less concentrated.

Back 1

Diffusion

Front 2

The process in which energy is released from complex molecules, such as glucose, within cells and transferred to molecules of ATP.

Back 2

Respiration

Front 3

A measure of the ability of water molecules to move freely in solution. Decreased by the presence of solutes.

Back 3

Water potential

Front 4

Movement of substances across membranes against their concentration gradient, requiring the use of energy in the form of ATP.

Back 4

Active transport

Front 5

To make narrow. For example, in the narrowing of blood vessels.

Back 5

Constrict

Front 6

The difference in molecular concentration that allows diffusion to occur.

Back 6

Diffusion gradient

Front 7

Pressure created by a fluid pushing against the sides of a container.

Back 7

Hydrostatic pressure

Front 8

A cavity surrounded by a cell wall in cells, such as xylem vessels, which have lost their cell contents. Also used for the central cavities of blood vessels.

Back 8

Lumen

Front 9

The movement of water molecules from a region of higher water potential to a region of lower water potential across a partially permeable membrane.

Back 9

Osmosis

Front 10

Process by which plants, some bacteria and some protoctists make food using carbon dioxide, water and sunlight energy.

Back 10

Photosynthesis

Front 11

Small air sacs in the lungs.

Back 11

Alveoli

Front 12

A molecule used to store energy temporarily in organisms. The molecule is broken down to adenosine diphosphate + phosphate to release energy to drive metabolic processes.

Back 12

ATP

Front 13

A cell in the phloem involved in actively loading sucrose into the sieve tube elements, to which it is linked by many plasmodesmata.

Back 13

Companion cell

Front 14

Tissue in plant roots and stems between epidermis and vascular tissue.

Back 14

Cortex

Front 15

A tissue that lines the inside of a structure, such as a blood vessel.

Back 15

Endothelium

Front 16

A tissue that covers the outside of a structure.

Back 16

Epithelium

Front 17

All the chemical reactions that take place in an organism.

Back 17

Metabolism

Front 18

The organelle found in cells in which most of the ATP synthesis occurs. It is the site of aerobic respiration.

Back 18

Mitochondrion

Front 19

Describes blood carrying oxygen in the form of oxyhaemoglobin.

Back 19

Oxygenated

Front 20

The tissue in plants that is used to transport dissolved sugars and other substances.

Back 20

Phloem

Front 21

Thin areas in the lignified walls of xylem tissue cells that allow communication between adjacent cells.

Back 21

(Bordered) Pits

Front 22

The membrane that surrounds every cell, forming the selectively permeable boundary between the cell and its environment.

Back 22

Plasma membrane

Front 23

Cells in the epithelium of roots that have long extensions to increase surface area for the absorption of water and minerals.

Back 23

Root hair cells

Front 24

A cell in phloem tissue through which sap is transported. It has very little cytoplasm, no nucleus, and non-thickened cellulose cell walls, with the end walls perforated.

Back 24

Sieve tube element

Front 25

A blood supply where blood flows through the heart once during each complete circuit of the body.

Back 25

Single circulatory system

Front 26

A type of muscle (involuntary muscle) found mostly in certain internal organs and involved in involuntary movements such as peristalsis.

Back 26

Smooth muscle

Front 27

The loss of water vapour from the aerial parts of a plant due to evaporation.

Back 27

Transpiration

Front 28

Describes a cell that is full of water as a result of entry of water due to osmosis such that pressure of the cell wall prevents more water entering.

Back 28

Turgid

Front 29

A plant tissue containing vessels (and other cells) that are used to transport water in a plant and provide support.

Back 29

Xylem

Front 30

Force of attraction between molecules of two different substances.

Back 30

Adhesion

Front 31

An attractive force between substances or particles. Often used to describe the strength of the interaction between enzyme and substrate.

Back 31

Affinity

Front 32

The route taken by water between the cells or through the cell walls in a plant.

Back 32

Apoplast pathway

Front 33

Term usually applied to the process of incorporating simple molecules of food produced by digestion into the living cells of an animal for use in metabolism.

Back 33

Assimilation

Front 34

A patch of tissue in the septum of the heart that conducts the electrical stimulus from the atria in the heart through to the Purkyne fibres.

Back 34

Atrioventricular node

Front 35

Valves between the atria and ventricles that prevent backflow of blood.

Back 35

Atrioventricular valves

Front 36

One of the upper chambers in the heart.

Back 36

Atrium

Front 37

The effect of carbon dioxide concentration on the affinity of haemoglobin for oxygen.

Back 37

Bohr effect

Front 38

Airways in the lungs that lead from the trachea to the bronchioles.

Back 38

Bronchi

Front 39

Airways in the lungs that lead from the bronchi to the alveoli.

Back 39

Bronchioles

Front 40

A chemical system that resists changes in pH by maintaining a constant level of hydrogen ions in solution. Certain chemicals dissolved in the solution are responsible for this.

Back 40

Buffer

Front 41

Plant tissue in the stem and root that contains dividing cells.

Back 41

Cambium

Front 42

The molecule resulting from combination of carbon dioxide and haemoglobin.

Back 42

Carbaminohaemoglobin

Front 43

A class of biological molecules with the general formula (CH2O)n. It includes sugars, starches, glycogen and cellulose.

Back 43

Carbohydrate

Front 44

The sequence of events making up one heartbeat.

Back 44

Cardiac cycle

Front 45

The muscle found in the heart. It has its own intrinsic heartbeat (it is myogenic).

Back 45

Cardiac muscle

Front 46

A flexible, slightly elastic connective tissue.

Back 46

Cartilage

Front 47

A flexible structure that holds the airways open.

Back 47

Cartilage ring

Front 48

A strip of waterproof material (suberin) in the cell walls of root endodermis cells. It blocks the apoplast pathway.

Back 48

Casparian strip

Front 49

A carbohydrate polymer (of beta-glucose) that forms plant cell walls.

Back 49

Cellulose

Front 50

The movement of certain anions ions into red blood cells to balance the loss of hydrogencarbonate ions.

Back 50

Chloride shift

Front 51

Short extensions of eukaryotic cells, typically 2–10 µm long and 0.03 µm in diameter. Used for locomotion or to move fluids or mucus over a surface.

Back 51

Cilia

Front 52

Lining cells that have cilia on their cell surface.

Back 52

Ciliated epithelium

Front 53

The attraction between water molecules due to hydrogen bonding.

Back 53

Cohesion

Front 54

A structural fibrous protein found in connective tissue, bones, skin and cartilage. It accounts for 30% of body protein.

Back 54

Collagen

Front 55

Vessels that carry blood to the heart muscle.

Back 55

Coronary arteries

Front 56

A protein in a cell membrane that allows movement of one molecule when linked to the movement of another molecule in the same direction by active transport.

Back 56

Cotransporter

Front 57

Blood with haemoglobin that carries no or little oxygen.

Back 57

Deoxygenated

Front 58

A sheet of muscular and fibrous tissue separating the chest cavity from the abdominal cavity.

Back 58

Diaphragm

Front 59

The period when the heart muscle in the ventricles is relaxing and blood pressure is at its lowest.

Back 59

Diastole

Front 60

To make wider. For example, when the lumens of blood vessels open more.

Back 60

Dilate

Front 61

The separation of a molecule into two molecules, atoms or ions without breakage of a covalent bond. For example, the release of oxygen from oxyhaemoglobin.

Back 61

Dissociation

Front 62

The curve on a graph showing the proportion of haemoglobin that is saturated with oxygen at different oxygen tensions.

Back 62

Dissociation curve

Front 63

A transport system in which blood travels twice through the heart for each complete circuit of the body.

Back 63

Double circulatory system

Front 64

Long fibres of the protein elastin that have the ability to stretch and recoil.

Back 64

Elastic fibres

Front 65

Tissue containing the protein elastin, which is able to stretch and recoil.

Back 65

Elastic tissue

Front 66

Trace (graph) showing the electrical activity of the heart muscle (atria and ventricles) during a cycle.

Back 66

Electrocardiogram

Front 67

A ring of cells between the cortex of a root and the area housing the xylem and phloem.

Back 67

Endodermis

Front 68

A protein molecule that acts as a biological catalyst.

Back 68

Enzyme

Front 69

Red blood cells.

Back 69

Erythrocytes

Front 70

A specialised area adapted to make it easier for molecules to cross from one side of the surface to the other.

Back 70

Exchange surface

Front 71

The passive movement of molecules across membranes down their concentration gradient. Aided by transport proteins but no metabolic energy is required.

Back 71

Facilitated diffusion

Front 72

Mixture of lipids, mainly triglycerides with saturated fatty acids, that is solid at body temperature. Act as an energy store, insulation, waterproofing and may give buoyancy.

Back 72

Fat

Front 73

A state in which the chambers in the heart contract out of rhythm.

Back 73

Fibrillation

Front 74

A term used to describe plant tissue where the cells have lost turgor and are not firm.

Back 74

Flaccid

Front 75

A 6-carbon monosaccharide sugar. Very important source of energy within cells. Substrate for glycolysis.

Back 75

Glucose

Front 76

Mucus-secreting cells in epithelial tissue.

Back 76

Goblet cells

Front 77

In pairs, these form the stomatal pore in the epidermis plants. They control the opening and closing of the pore by changes in their turgidity.

Back 77

Guard cells

Front 78

The iron-containing prosthetic group found in haemoglobin.

Back 78

Haem

Front 79

The protein that carries oxygen in the red blood cells.

Back 79

Haemoglobin

Front 80

The acid produced when haemoglobin takes up hydrogen ions.

Back 80

Haemoglobinic acid

Front 81

Muscles between the ribs, responsible for moving the rib cage during breathing.

Back 81

Intercostal muscle

Front 82

General term for white blood cells.

Back 82

Leucocytes

Front 83

A waterproofing substance that impregnates the walls of xylem tissue and that gives wood its strength.

Back 83

Lignin

Front 84

A system of lymph nodes and lacteals with lymph fluid.

Back 84

Lymphatic system

Front 85

A type of white blood cell activated as part of the immune response that provides antibodies and cellular immunity.

Back 85

Lymphocyte

Front 86

Undifferentiated plant cells capable of rapid cell division.

Back 86

Meristem

Front 87

A slimy substance secreted by goblet cells in animal epithelial tissues. It is made up mostly of glycoproteins and protects and/or lubricates the surface on to which it is secreted.

Back 87

Mucus

Front 88

Describes muscle tissue (heart muscle) that generates its own contractions.

Back 88

Myogenic

Front 89

The amount of oxygen in the air expressed as the pressure created by the presence of oxygen, expressed in kilopascals (kPa).

Back 89

Oxygen tension

Front 90

Haemoglobin with oxygen molecules attached.

Back 90

Oxyhaemoglobin

Front 91

Relatively unspecialised plant cells. They have living contents and thin, permeable cellulose cell walls. They may be able to photosynthesise, store food or support young plants.

Back 91

Parenchyma

Front 92

The proportion of total pressure provided by a particular gas as part of a mixture of gases.

Back 92

Partial pressure

Front 93

A layer of cells in the root that lies just inside the endodermis. It usually consists of meristematic cells whose division gives rise to lateral roots.

Back 93

Pericycle

Front 94

Muscular contractions of muscle layers of gut to squeeze food along.

Back 94

Peristalsis

Front 95

Detachment of the plasma membrane from the cell wall as the cytoplasm shrinks when water is lost from a plant cell.

Back 95

Plasmolysis

Front 96

Fragments of cells in the blood that play a part in blood clotting.

Back 96

Platelets

Front 97

A polymer consisting of many amino acid monomers covalently bonded together.

Back 97

Polypeptide

Front 98

Apparatus used to measure water uptake in a leafy shoot and so to estimate rate of transpiration.

Back 98

Potometer

Front 99

A polymer consisting of many amino acid monomers covalently bonded together.

Back 99

Protein

Front 100

The circulation of the blood through the lungs.

Back 100

Pulmonary circulation

Front 101

The vein carrying oxygenated blood from the lungs to the left atrium of the heart.

Back 101

Pulmonary vein

Front 102

Specialised tissue (muscle fibres) in the septum of the heart that conducts the electrical stimulus from the sinoatrial node to the ventricles.

Back 102

Purkyne tissue

Front 103

Valves between the ventricles and the main arteries leading out of the heart, which prevent backflow of blood.

Back 103

Semilunar valves

Front 104

The wall separating the ventricles of the heart.

Back 104

Septum

Front 105

A part of a plant that removes sugars from the phloem.

Back 105

Sink

Front 106

The patch of tissue that initiates the heartbeat by sending waves of excitation over the atria.

Back 106

Sinoatrial node

Front 107

A solid that dissolves in a liquid.

Back 107

Solute

Front 108

A part of the plant that releases sugars into the phloem.

Back 108

Source

Front 109

The ‘skin’ on the surface of water formed as a result of hydrogen bonding in water molecules pulling the surface molecules downwards.

Back 109

Surface tension

Front 110

A chemical that can reduce the surface tension of a film of water.

Back 110

Surfactant

Front 111

The route taken by water through the cytoplasm of cells in a plant.

Back 111

Symplast pathway

Front 112

The circulation that carries blood around the body, excluding the circulation to the lungs.

Back 112

Systemic circulation

Front 113

The stage of the heart cycle in which heart muscle contracts to pump blood.

Back 113

Systole

Front 114

String-like tendons used to attach the atrioventricular valves of the heart to the sides of the ventricle wall. Sometimes called heart strings.

Back 114

Tendinous cords

Front 115

A group of similar cells that perform a particular function.

Back 115

Tissue

Front 116

The fluid, derived from blood plasma, that surrounds the cells in a tissue.

Back 116

Tissue fluid

Front 117

The windpipe leading from the back of the mouth to the bronchi.

Back 117

Trachea

Front 118

The movement of sucrose and other substances up and down a plant.

Back 118

Translocation

Front 119

The pathway taken by water in plants as it passes from cell to cell via the cell cytoplasm and vacuole.

Back 119

Vacuolar pathway

Front 120

The transport tissue in a plant – usually found as a bundle containing both xylem and phloem.

Back 120

Vascular tissue

Front 121

Either of two large veins that carry deoxygenated blood from the body back to the heart.

Back 121

Vena cava

Front 122

Breathing – movement of diaphragm and rib cage that bring air into and out of the lungs.

Back 122

Ventilation

Front 123

The lower chambers in the heart that pressurise the blood when they contract.

Back 123

Ventricle

Front 124

The potential energy of water vapour in a gas – it is used to indicate how much water vapour is present.

Back 124

Water vapour potential

Front 125

A plant specially adapted to living in dry areas.

Back 125

Xerophyte

Front 126

Minute vessels connecting arteries to veins that provide the exchange surface for tissues to obtain oxygen and nutrients.

Back 126

Capillary

Front 127

Breathing in.

Back 127

Inspiration

Front 128

Breathing out.

Back 128

Expiration

Front 129

Apparatus for measuring breathing rate, volume and oxygen uptake.

Back 129

Spirometer

Front 130

The maximum volume of air that can be exchanged in the lungs.

Back 130

Vital capacity

Front 131

The volume of air that is exchanged in the lungs at rest.

Back 131

Tidal volume

Front 132

The movement of oxygen, nutrients, hormones and waste around the body.

Back 132

Transport

Front 133

The main artery leaving the heart taking oxygenated blood to the systemic circulation.

Back 133

Aorta

Front 134

The artery carrying deoxygenated blood from the heart to the lungs.

Back 134

Pulmonary artery

Front 135

Form of blood supply where blood cells remain within vessels.

Back 135

Closed circulatory system

Front 136

Form of blood supply where blood cells permeate freely through the tissues.

Back 136

Open circulatory system

Front 137

The gas exchange system in fish.

Back 137

Gills

Front 138

Fluid that drains back to the venous circulation via the lymphatic system.

Back 138

Lymph

Front 139

Form of haemoglobin with higher affinity for oxygen than adult haemoglobin.

Back 139

Fetal haemoglobin

Front 140

A slight change in the three dimensional structure of a protein that may result in a change in activity. Often involved in regulation of enzyme activity.

Back 140

Conformational change

Front 141

Form of haemoglobin involved in transport of carbon dioxide.

Back 141

Carbaminohaemoglobin

Front 142

Anion formed by the dissociation of carbonic acid in the blood.

Back 142

Hydrogen carbonate

Front 143

Formed when carbon dioxide dissolces in water - formation is catalysed by the enzyme carbonic anhydrase.

Back 143

Carbonic acid

Front 144

Enzyme catlaysing the formation of carbonic acid from carbon dioxide and water.

Back 144

Carbonic anhydrase

Front 145

The hydrostatic pressure resulting from the osmotic movement of water.

Back 145

Pressure potential

Front 146

Disaccharide used by plants for transporting sugar from leaves to sinks.

Back 146

Sucrose