Vocabulary Flashcards
(238 cards)
1
Q
a helical structure formed by a polypeptide chain, held in place by hydrogen bonds; an example of secondary structure in a protein
A
alpha-helix
2
Q
the energy that must be provided to make a reaction take place; enzymes reduce the ____ required for a substrate to change into a product
A
activation energy
3
Q
immunity gained when an antigen enters the body, an immune response ovvurs and antibodies are produced by plasma cells
A
active immunity
4
Q
an area on an enzyme molecule where the substrate can bind
A
active site
5
Q
the movement of molecules or ions through transport proteins across a cell membrane, against their concentration gradient, using energy form ATP
A
active transport
6
Q
nitrogen-containing purine base found in DNA and RNA
A
adenine (A)
7
Q
one of the products from hydrolysis of ATP
A
adenosine diphosphate (ADP)
8
Q
a hormone secreted by the adrenal glands in times of stress or excitement
A
adrenaline
9
Q
plant tissue containing air spaces
A
aerenchyma
10
Q
a particular variety of a gene
A
allele
11
Q
a polymer of alpha-glucose monomers linked by both 1, 4 and 1, 6 lindages, forming a branched chain; a constituent of starch
A
amylopectin
12
Q
a polymer of apha-glucose monomers linked by 1, 4 linkages, forming a curving chain; a constituent of starch
A
amylose
13
Q
a substance produced by a living organism that is capable of killing or inhibiting the growth of a microorganism
A
antibiotic
14
Q
a glycoprotein (immunoglobulin) made by plasma cells derived from B-lymphocytes, secreted in response to an antigen; the variable region of the antobody molecule is complementary in shape to its spectitic antigen
A
antibody
15
Q
sequence of three unpaired bases on a tRNA molecule that binds with a codon on mRNA
A
anticodon
16
Q
a substance that is foreign to the body and stimulates an immune response
A
antigen
17
Q
the non-living system of interconnected cell walls extending throughout a plant, used a s a transport pathway for the movement of water and mineral ions
A
apolastic pathway
18
Q
small blood vessel that carries blood from arteries to capillaries; determine how much blood flows through capillaries
A
arteriole
19
Q
a blood vessel that carries blood away from the heart; it has a relatively thich wall and contains large amounts of elastic fibres
A
artery
20
Q
immunity gained either by vaccination (active) or by injecting antibodies (passive)
A
artificial immunity
21
Q
the universal energy currency of cells
A
adenosine triphosphate (ATP)
22
Q
the enzyme catalysing the phosphorylation of ADP to ATP
A
ATP synthase
23
Q
a patch of tissue in the septum of the heart through which the wave of electrical excition is passed from the atria to the Purkyne tissue
A
atrioventricular node
24
Q
a type of disease in whcih there is a mistaken immune response to a self antigen leading to the production of antibodies and the destruction of body tissues; myasthenia gravis is an example
A
autoimmune disease
25
all the chromosomes except the X and Y (sex) chromosome
autosomes
26
an enzyme made by antibiotic-resistant bacteria that breaks down penicillin molecules
beta-lactamase
27
a loose, sheet-like structure formed by hydrogen bonding between parallel polypeptide chains; an example of secondary structure in a protein
beta-pleated sheet
28
a type of lymphocyte that gives rise to plasma cells and secretes antibodies
B-lymphocyte
29
a test for the presence of reducing sugars; the unknown substance is heated with _____, and a change from a clear blue soluion to the production of a yellow red or brown precipitate indicates he presence of reducing sugars such as glucose
Benedict's test
30
a test for the presence of amine groups and thus for the presence of proteins; ____ is added to the unknown substance, and a change from pale blue to purple indicates the presence of proteins
biuret test
31
the decrease in affinity of haemoglobin for exygen that occurs when carbon dioxide is present
Bohr effect
32
a disease in whci the airways in the lungs become inflamed and congested with mucus;___ often associated with smoking
bronchitis (chronic)
33
the apparatus in which the energy value of a compound can be measured by burning it in oxygen
calorimeter
34
a disease, often but not always treatbale, that results from a breakdown in the usual control mechanisms that regulate cell division; certain cells divide uncontrollably and form tumours, from which cells may bread away and form secondary tumours in other arease of the body (metastasis)
cancer
35
the smallest type of blood vessel, whose function is facilitate exchange of substances between the blood and the tissues; capillary walls are made up of a single layer of squamous epithelium, and their internal diameter is only a little larger than that of a red blood cell
capillary
36
a substance that can cause cancer
carcinogen
37
the sequence of events taking place during one heart beat
cardiac cycle
38
the muscle tissue that makes up most of the heart; striated
cardiac muscle
39
degeneratice diseases of the heart and circulatory system e.g. coronary heart disease or stroke
cardiovascular diesease
40
someone who is infected with a pathogen bust does not show any symptoms of the disease; people like his can be sources of infection that are hard to trave
carrier
41
a type of membrane protein which changes shape oto allow the passage into or out of the cell of specific ions or molecules by facilitated diffusion or active transport
carrier protein
42
the basic unit of all living organisms; it is srrounded by a cell surface membrane (alsoknown as the pasma membrane) and contains cytoplasm and organelles
cell
43
the sequence of events that takes place from one cell division until the next; it is made up of interphase, mitosis and cytokinesis
cell cycle
44
the molecular mechanisms by which cells detect and respond to external stimuli, including communication between cells
cell signalling
45
a very thin membrane (about 7nm diameter) surrounding all cells; it is partially permeable and controls the exchange of materials between the cell and its environmnt
cell surface membrane
46
a wall surrounding prokaryote, plant and fungal cells; contains a strengthening material which protects the cell from mechanical damage, supports it and prevents it from bursting by osmosis if the cell is surroudned by a solution with a higher water potential
cell wall
47
one of two small, cylindrical structures, made from microtubules, found just outside the nucleus in animal cells, in a region known as the centrosome; they are also found at the bases of cilia and flagella
centriole
48
a membrane protein of fixed shape which has a water-filled pore through whcih selected hydrophilic ions or molecules can pass; aid facilitated diffusion
channel protein
49
a green pigment responsible for light capture in photosynthesis in algae and plants
chlorophyll
50
the photosynthetic orgelle in eukaryotes
chloroplast
51
a small, lipid-related molecule with a hydrophilic head and a hydrophobic tail which is an essential constituent of membranes, particularly in animal cells, conferring fluidity, flexibility and stability to the membrane
cholesterol
52
one of two identical parts of a chromosome, held together by a centromere, formed during interphase by the replication of the DNA strand
chromatid
53
the loosely coiled form of chromosomes during interphase of the cell cycle; made of DNA and proteins and is visible as loosely distributed patches or fibres within the nucleus when stained
chromatin
54
a structure made of DNA and histones, found in the nucleus of a eukaryotic cell; the term bacterial _____ is now commenly used for the circular strand of DNA present in a prokaryotic cell
chromosome
55
a random and unpredictable change in the structure or number of chromosomes in a cell
chromosome mutation
56
a disease of the lungs characterised by bronchitis and emphysema
chronic obstructive pulmonary disease (COPD)
57
sequence of three bases on an mRNA molecule that codes for a specific amino acid or for a stop signal
codon
58
a modified form of parenchyma in which the corners of the cells have extra cellulose thickening, providing extra support, as in the midrib of leaves and at the corners of square stems; in three dimensions the tissue occurs in strands (as in celery petioles)
collenchyma
59
a cell with an unthickened cellulose wall and dense cytoplasm that is found in close association with a phloem sieve element to which it is directly linked via many plasmodesmata; ____ and the sieve element form a functional unit
companion cell
60
when a substance reduces the rate of activity of an enzyme by competing with the substrate molecules fo rthe enzyme's active site; increasing the concentration of the substrate reduces the degree of inhibition
competitive inhibition
61
the hydrogen bonding of A with T or Uand of C with G in nucleic acids
complementary base pairing
62
a chemical reaction involving the joining together of two molecules by removal of a water molecule
condensation reaction
63
an experiment in which the factor whose effect if being investigated (the independent variable is absent); it is used as a standard of comparison
control experiment
64
variables (factors) that are kept constant in an experiment; only the independent variable should be changed
controlled variables / standardised variables
65
a disease of heart caused by damage to the coronary arteries
coronary heart disease
66
a fold of the inner membrane of the mitochondrial envelope on which are found stalked particles of ATP synthase and electron transport chains associated with aerobic respiration
crista, plural: cristae
67
the contents of a cell excluding the nucleus
cytoplasm
68
nitrogen-containing pyrimidine base found in DNA and RNA
cytosine (C)
69
a pentose (5C) sugar found in DNA
deoxyribose
70
in an experiment, the variable that changes as a result of changing the independent variable
dependent variable
71
the net movement of molecules or ions from a region of higher concentration to a region of lower concentration down a gradient, as a result of the random movements of particles
diffusion
72
one that possesses two complete sets of chromosomes; 2n
diploid cell
73
a sugar molecule consisting of two monosaccharides joined together by a glycosidic bond
disaccharide
74
an enzyme that catalyses the linkage of nucleotides during the formation of a DNA molecule
DNA ligase
75
a circulatory system in which the blood travels twice through the heart on one complete circuit of the body; the pathway from heart to lungs and bck to the heart is known as the pulmonary ciculation, and that from heart to the rest of the body and back to the heart as the systemic circulation
double circulation
76
a disease in which alveoli are destroyed, giving large air spaces and decreased surface area for gaseous exchange; it is often associated with chronic bronchitis
emphysema
77
the bulk movement of liquids (pinocytosis) or solids (phagocytosis) into a cell, by the infolding of the cell surface membrane to form vesicles containing the substance; an active process requiring ATP
endocytosis
78
a network of flattened sacs running through the cytoplasm of eukaryotic cells; molecules, particularly proteins, can be transported through the cell inside the sacs separate from the rest of the cytoplasm;is continuous with the outer membrane of the nuclear envelope
endoplasmic reticulum (ER)
79
a tissue that lines the inside of a structure, such as the inner surface of a blood vessel
endothelium
80
a protein produced by a living organism that acts as a catalyst in a specific reaction by reducing activation energy
enzyme
81
a tissue that covers the outside of a structure
epithelium
82
a cell containing a nucleus and other membrane-bound organelles
eukaryotic cell
83
the bulk movement of liquids or solids out of a cell, by the fusion of vesicles containing the substance with the cell surfave membrane; an active process requiring ATP
excytosis
84
the diffusion of a substance through transport proteins in a cell membrane; the proteins procide hydrophilic areas that allow the molecules or ions to pass through the membrane which would otherwise be less permeable to them
facilitated diffusion
85
a protein whose molecules have a relatively long, thin sructure that is generally insoluble and metabolically inactive, and whose function is usually structural, e.g. keratin and collagen
fibrous protein
86
the currently accepted basic model of membrane structure, proposed by Singer and Nicolson in 1972, in which protein molecules are free to move about in a fluid bilayer of phospholipid molecules
fluid mosaic model
87
a haploid cell specialised for fertilisation
gamete
88
gthe movement of gases between an organism and its environment, e.g. the intake of oxygen and the loss of carbon dioxide;often takes place across a specialised surfave such as the alveoli of the lungs
gas exchange
89
a length of DNA that codes for a particular protein or polypeptide
gene
90
a change in the base sequence in part of a DNA molecule
gene mutation
91
cells that can divide to form gametes
germ cells
92
a protein which forms the basic unit of a group of proteins that bind oxygen, namely myoglobin and different forms of haemoglobin; has a characteristic tertiary structure; exists in several closely similar forms such as alpha-, beta-, gamma-_____
globin
93
a protein whose molecules are folded into a relatively spherical shape, and which is often water-soluble and metabolically active, e.g. insulin and haemoglobin
globular protein
94
a polysaccharide made of many glucose molecules linked together, that acts as a glucose store in liver and muscle cells
glycogen
95
a coc link between two monosaccharide molecules, formed by a condensation reaction
glycosidic bond
96
an organelle found in eukaryotic cells; consists of a stack of flattened sacs, constantly forming at one end and breading up into ___ vesicles at the other end; chemically modifies the molecules it transports; e.g. sugars may be added to proteins to make glycoproteins
Golfi body/apparatus/complex
97
a stack of circular thylakoids in a chloroplast
granum, plural: grana
98
nitrogen-containing purine base found in DNA and RNA
guanine (G)
99
a sausage-shaped epidermal cell found with another, in a pair bounding a stoma and controlling its opening or closure
guard cell
100
the red pigment found in red blood cells, whose molecules contain four iron atoms within a globular protein made up of four polypeptides, and that combines reversibly with oxygen
haemoglobin
101
one that possesses one complete set of chromosomes; N
haploid cell
102
a pair of chromosomes in a diploid cell that have the same structure as each other, with the same genes (but not necessarily the same alleles of those genes) at the same loci, and that pair together to form a bivalent during the first division of meiosis
homologous chromosomes
103
a substance secreted by an endocrine gland, that is carried in blood plasma to another part of the body where it has an effect
hormone
104
a relatively weak bond formed by the attraction between a group with a small positive charge on a hydrogne atom and another group carrying a small negative chare, e/g/ between OH groups
hydrogen bond
105
a reaction in which a complex molecule is bronken down to simpler ones, involving the addition fo water
hydrolysis
106
enzymes that have been fixed to a surfave or within a bead of agar gel
immobilised enzymes
107
the complex series of responses of the body to the entry of a foreign antigen; involves the activity of lymphocytes and phagocytes
immune response
108
the body's defence system
immune system
109
protection against infectiour diseases, gained either actively or passively
immunity
110
an antibody
immunoglobulin
111
the ability of the immune system to respond quickly to antigens that it recogises as having entered the body before
immunological memory
112
the variable (factor) that is deliberately changed in an experiment
independent variable
113
a moel for enzyme action; the substrate is a complementary shape the the active site of the enzyme, but not an exact fit - the enzyme or sometimes substrate can change shape slightly to ensure a perfect fit
induced fit hypothesis
114
a disease caused by an organism such a bacterium or virus
infection disease
115
the range of values into which the middle 50% of a set of data falls
interquartile range
116
atoms of the same element with differenet atomic mass number
isotopes
117
a photograph or diagram of a set of chromosomes from an individual; the chromosomes are normally arranged in their homologous pairs in order of size; sex chromosomes may be shown separately
karyogram
118
a protein structure found at the centromere of a chromatid to which microtubules attach during cell division
kinetochore
119
cancer of the stem cells that give rise to white blood cells
leukaemia
120
the one factor, of many affecting a process, that is nearest its lowest value and hence is rate-limiting
limiting factor
121
a model for enzyme action; the substrate is a complementary shape to the active site of the enzyme, and fits exactly into the site
lock and key hypothesis
122
the position at which a particular gene is found on a particular chromosome; the same gene is always found at the same ____
locus
123
an almost colourless fluid, very similar in composition to blood plasma but with fewer plasma proteins, that is present in lymph vessels
lymph
124
a type of white blood cell that is involved in the immune response; unlike phagocytes they become active only in the presence of a particular antigen that 'matches' their specific receptors or antibodies
lymphocyte
125
a spherical organelle found in eukaryotic cells; contains digestive (hydrolytic) enzymes and has a variety of destructive functions, such as removal of old cell organelles
lysosome
126
a large biological molecule such as a protein, polysaccharide or nucleic acid
macromolecule
127
phagocytic cell found in tissues throughout the body; they act as antigen-presenting cells (APCs)
macrophage
128
the number of times greater that an image is than the actual object; = image size/actual (real) size of the object
magnification
129
the middle value of all the values in a set of data showing a normal distribution
median
130
lymphocytes which develop during an immune response and retain the ability to respond quickly when an antigen enters the body on a second or any subsequent occasion
memory cells
131
the internal tissue of a leaf blade with chloroplasts for photosynthesis and consisting of an upper layer of palisade ____ (the main photosynthetic tissue) and a lower layer of spongy ___ with large air spaces for gas exchange
mesophyll
132
a single-stranded RNA molecule that carries the genetic code from DNA to a ribosome
messenger RNA (mRNA)
133
the substrate concentration at which an enzyme works at half its maximum rate (1/2Vmax), used as a measure of the efficiency of an enzyme; the lower the value of __, the more efficient the enzyme
Michaelis-Menten constant (Km)
134
tiny tubes made of a protein called tubulin and found in most eukaryotic cells; have a large variety of functions, including cell support and determining cell shape; the 'spindle' on which chromosomes separate during nuclear division is made of ____
microtubules
135
the organelle in eukaryotes in which aerobic respiration takes place
mitochondiron, plural: mitochondria
136
the division of a nucleus into two so that the two daughter cells have exactly the same number and type of chromosomes as the parent cell
mitosis
137
the value that occurs most frequently in a set of data showing a normal distribution
mode (modal class)
138
many identical antibodies, made by hybridoma cells formed by the fusion of a plasma cell and a cancer cell
monoclonal antibodies
139
a relatively simple molecule which is used as a basic building block for hte synthesis of a polymer, usually by condensation reactions; common examples of molecules used as ___ are monosaccharides, amino acids and nucleotides
monomer
140
a substance that can cause mutation
mutagen
141
an unpreductable change in the structure of DNA, or in the structure and number of chromosomes
mutation
142
immunity gained by being infected (active) or by receiving antibodies from the mother across the placenta or in breast milk (passive)
natural immunity
143
a phagocytic white blood cell
neutrophil
144
a chemical found in tabacco smake that can bind with acetylcholine receptors on the postsynaptic membrane of cholinergic synapses
nicotine
145
when a substance reduces the rate of activity of an enzyme, but increasing the concentration of the substrate does not reduce the degree of inhibition; many ___ors bind to areas of the enzyme molecule other than the active site itself
non-competitive inhibition
146
any disease not caused by a pathogen
non-infectious disease
147
any substance or cell that is recognised by the immune system as being foreign and will stimulate an immune response
non-self
148
a pattern shown by a set of data that are distributed symmetrically on both sides of the mean value
normal distribution
149
the two membranes, situated closely togethe, that surround the nuvleus; the envelope is perforated with nuclear pores
nuclear envelope
150
pores found in the nuclear envelope which control the exchange of materials, e.g. mRNA, between the nucleus and the cytoplasm
nuclear pores
151
a small structure, one or more of which is found inside the nucleus; the nucleolus is usually visible as a densely stained body; its function is to manufacture ribosomes using the information in its own DNA
nucleolus
152
a bead-like structure made of eight histone molecules, around which DNA is wrapped; the fundamental subunits of chromatin
nucleosome
153
a molecule consisting of a nitogen-containing base, a pentose sugar and a phosphate group
nucleotide
154
a relatively large organelle found is eukaryotic cells but absent from prokaryotic cells; the nuvleus contains the cell's DNA and therefor controls the activities of the cell
nucleus
155
a hypothesis that assumes there is no relationship between two variables, or that there is no significant difference between two samples
null hypothesis
156
a functionally and structurally distinct part of a cell, e.g. a ribosome or mitochondrion
organelle
157
a compound containing carbon and hydrogen
organic molecule
158
the net movement of water molecules from a region of higher water potential to a region of lower water potential, through a partially permeable membrane, as a result of their random motion (diffusion)
osmosis
159
a basic plant tissue typically used as packing tissue between more specialised strucutes; it is metabolically active and may have a variety of functions such as food storage, support and transport via symplast and apoplast pathways
parenchyma
160
immunity gained without an immune response; antibodies are injuected (artificial) or pass from mother to child across the placenta or in breast milk (natural)
passive immunity
161
an organism that causes infectious disease
pathogen
162
a C-N link between two amino acid molecules, formed by a condensation reaction
peptide bond
163
a substance, also known as murein, whose molecules are made of amino acid chains to which sugars are attached; bacterial cell walls contain peptioglycans; they make the wall more rigid, preventing the cell from bursting by osmosis when it is surrounded by a solution with a higher water potential
peptidoglycan
164
a type of cell that ingests and destroys pathogens or damaged body cells by the process of phagocytosis; some ___ are WBC
phagocyte
165
tissue containing sieve tubes and other types of cell, responsible for he translocation of assimilates such as sucrose through a plant
phloem
166
a substance whose molecules are made up of glycerol molecule, two fatty acids and a phosphate group; a bilayer of phopholipids forms the basic structure of all cell membranes
phospholipid
167
the transfer of a phosphate group to an organic compound
phosphorylation
168
a small, circular piece of DNA in a bacterium (not its main 'chromosome'; plasmids often contain genes that confer resistance to antibiotics)
plamid
169
a pore-like structure found in plant cell walls; ___ of neighbouring plant cells line up to form tube-like pores through the cell walls allowing the controlled passage of materials from one cell to the other; the pores contain DR and are lined with the cell surface membrane
plasmodesma, plural: plasmodesmata
170
a giant melecule made from many similar repeating subunits joined together in a chain; the subunits are much smaller and simpler molecules known as monomers; may also be referred to as macromolecules; e.g. polysaccharides, proteins and nucleic acids
polymer
171
a chain of nucleotides
polynucelotide
172
a long chain of amino acids formed by condensation reactions between the individual amino acids; proteins are mad of one or more ____ chains
polypeptide
173
a polymer whose subunits are monosaccharids joined togther by glycosidic bonds
polysaccharide
174
a pieve of apparatus used to measure the rate of uptake of water by a plant
potometer
175
the sequence of aminiacids in a polypeptide or protein
primary structure
176
a length of DNA that has a complementary base sequence to another pieve of DNA that you are trying to detect
probe
177
a cell that does not contain a nucleus or any other membrane-bound organelles; e.g. bacteria and archeans
prokaryotic cell
178
a length of DNA that controls the expression of a gene
promoter
179
a non-protein component that is attached to a protein to form a complex molecule; it aids the protein in its function; e.g. hearm group
prosthetic group
180
the living contents of a plant cell, including the cell surface membrane, but excluding the cell wall
protoplast
181
an area of tissue in the septum of the heart that conducts the wave of excitation from the atria to the base of the ventricles
Purkyne tissue
182
the 3D arrangement of 2 or more polypeptides, or of a polypeptide and a non-protein component
quaternary structure
183
a cell which is sensitive to a change in the environment and that may generate an action potential as a result of a stimulus
receptor cell
184
the ability to distinguish between two objects very close together; the higher the ____ of an image, the greater the detail that can be seen
resolution
185
enzymatic release of energy from organic compounds in living cells
respiration
186
a pentose sugar found in RNA
ribose
187
a tiny organelle found in large numbers in all cells prokaryotic ___ are smaller (70s, 20nm diameter)than eukaryotic ___ (80s, 25nm diameter); made of protien and ribosomal RNA and consist of two subunits; sites of protein synthesis in cels
ribosome
188
the structure of a protein molecule resulting from the regular coiling or folding of the chain of amino acids, e.g. an alpha-helix or beta-pleated sheet
secondary structure
189
refers to substances produced by the body that the immune system does not recognise as foreign, so do not stimulate an immune response
self
190
the method by whcih a DNA molecule is copied to form two identical molecule, each containing one strand from the original molecule an one newly synthesised strand
semi-conservative replication
191
the pair of chromosomes that determine the sex of an individual; in humans they are the X and Y chromosomes
sex chromosomes
192
a gene that is carried on an X chromosome but not on a Y chromosome
sex-linked gene
193
reproduction involving the fusion of gametes (fertilisation) to produce a zygote
sexual reproduction
194
a genetic disease caused by a faulty gene coding for haemoglobin, in which haemoglobin tends to precipitate when oxygen concentrations are low
sickle cell anaemia
195
a person who is heterozygous for the sickle cell allel is said to have _____; there are normally no symptoms, except occasionally in very severe conditions of oxygen shortage
sickle cell trait
196
a cell found in phloem tissue, with non-thickened cellulose walls, very little cytoplasm, no nucleus and end walls perforated to form sieve plates, through which sap containing sucrose is transported
sieve element / sieve tube element
197
tubes formed by sieve elements lined up end to end
sieve tube
198
a mutation in which the change in the DNA has no discernible effect on an organism
silent mutation
199
a patch of muscle in the wall of the gith atrium of the heart whose intrinsic rate of rhythmic contraction is faster than that of the the rest of the cardiac muscle, and from whcih waves of excitation spread to the rest of the heart to initiate its contraction during the cardiac cycle
sinoatrial node
200
type of muscle tissue found in walls of lood vessels (exvept capillaries), trachea, bronchi and bronchioles, alimentary canal and ureter; the muscel cells are not striated
smooth muscle
201
a membrane protein(s) that moves Na ions out of a cell and K ions into, using ATP
sodium-potassium pump
202
cells that are not involved in gamete formation
somatic cells
203
a measure of how widely a set of data is spread out on either isde of the mean
standard deviation
204
variables (factors) that are kept constant in an experiment; only the independent variable should be changed
standardised variables
205
a measure of how likely it is that a mean calculated from a sample represents the true mean for the whole population
standard error
206
a relatively unspecialised cell that retains the ability to divide an nlimited number of times
stem cell
207
a pore in the epidermis of a leaf, bounded by two guard cells and needed for efficient gas examge
stoma, plural: stomata
208
damage the the brain caused by bursting or blockage of an artery
stroke
209
the matrix of a chloroplast in which the light independent reactions of photosynthesis occur
stoma, plural: stomata
210
the living system of interconnected protoplasts extending throughout a plant, used as transport pathway for the movement of water and solutes; individual protoplasts are connected via plasmodesmata
symplast
211
a lymphocyte that does not secrete antibodies; __ helper ___ stimulate the immune system to respond during an infection and killer ____ destroy human cells that are infected with pathogens such as bacteira and viruses
T-lymphocyte
212
repetitive sequences of DNA at the end of chromosomes that protect genes from the chromosome shortening that happens at each cell division
telomeres
213
the compact structure of a protein molecule resulting from the 3D coiling of the already-folded chain of amino acids 2°
tertiary structure
214
a flattened, membrane-bound, fluid-filled sac, which is the site of the light-dependent reactions of photosynthesis in a chloroplast
thylakoid
215
nitrogen-containing pyrimidine base found in DNA
thymine (T)
216
the almost colourless fluid that fills the spaces between body cells; tissue fluid forms from the fluid that leaks from blood capillarie, and most of it eventually collects into lymph vessels where it forms lymph
tissue fluid
217
the partially permeable membrane that surrounds plant vacuoles
tissue fluid
218
the partially permeable membrane that surrounds plant vacuoles
tonoplast
219
production of an mRNA molecule on DNA
transcription
220
a folded, single-stranded RNA molecule that carries an amino acid to a ribosome for protein synthesis
transfer RNA (tRNA)
221
production of a polypeptide at a ribosome from the code on mRNA
translation
222
the transport of assimilates such as sucrose through a plant, in phloem tissue; requires the input of metabolic energy
translocation
223
the transfer of a pathogen from one person to another
transmission
224
the loss of water vapour from a plant to its environment, by diffusion down a water potential gradient; most transpiration takes place through the stmata in the leaves
transpiration
225
a lipid whose molecules are made up of glycerol molecule and three fatty acids
triglyceride
226
a statistical procedure used to determine whether the means of two samples differ significantly
t-test
227
nitrogen-containing pyrimidine base found in RNA
uracil (U)
228
the theoretical maximum rate of an enzyme-controlled reaction, obtained when all the active sites are occupied
Vmax
229
givin a vaccine containing antigens for a disease, either by injection or by mouth; confers artificial active immunity
vaccination
230
an organelle found in eukaryotic cells; a large permanent central vacuole is a typical feature of plant cells, where it has a variety of functions, including storage of biochemicals such as salts, sugars and waste products; temporary ____, such as phagocytic ____/vesicles, may form in animal cells
vacuole
231
a blood vessel that carries blood back towards the heart; it has relatively thin walls and contains valves
vein
232
very small (20-300nm) infectious particle which can replicate only inside living cells and consists essentially of a simple basic structure of a genetic code of DNA or RNA surrounded by a protein coat
virus
233
a channel protein through a cell membrane that opens or closes in response to changes in electrical potential across the membrane
voltage-gated channel
234
a measure of the tendency of water to move from one place to another; water moves from a solution with higher ___ to one with lower ____; decreased by the addition of solute, increased by the application of pressure; symbol is ψ or ψw
water potential
235
a plant adapted to survive in conditions where water is in short supply
xerophyte
236
a dead, empty tube with lignified walls, through which water is transported in plants; it is formed by xylem vessel elements lined up end to end
xylem vessel
237
a dead, lignified cell found in xylem specialised for transporting water and support; the ends of the cells break down and join with neighbouring elements to form longtubes called xylem vessels
xylem vessel element
238
a cell formed by the fusion of two gametes; nornally the gametes are haploid and ___ is diploid
zygote
