Communication, homeostasis and energy (Module 5) Flashcards
(106 cards)
1
Q
Cell signalling
A
the way in which cells communicate with each other
2
Q
Effector
A
Cell, tissue or organ that brings about a response
3
Q
Homeostasis
A
Maintaining a constant internal environment despite changes in external and internal factors
4
Q
Negative feedback
A
The mechanism that reverses a change, bringing the system back to the optimum
5
Q
Positive feedback
A
The mechanism that increases a change, taking the system further away from the optimum
6
Q
Sensory receptors
A
Cells/sensory nerve endings that respond to a stimulus in the internal or external environment of an organism and can create action potentials
7
Q
Ectotherm
A
Organism that relies on external sources of heat to maintain body temperature
8
Q
Endotherm
A
Organism that uses heat from metabolic reactions to maintain body temperature
9
Q
Hypothalamus
A
Part of the brain that coordinates homeostatic responses
10
Q
Excretion
A
Removal of metabolic waste from the body
11
Q
Metabolic waste
A
A substance that is produced in excess by the metabolic processes in the cells, it may become toxic
12
Q
Hepatic artery
A
Oxygenated blood from the heart - aorta - hepatic artery - liver
13
Q
Hepatic portal vein
A
Deoxygenated blood from digestive system enters liver via hepatic portal vein
14
Q
Hepatocytes
A
Liver cells
15
Q
Sinusoid
A
Chamber where blood from the hepatic portal vein and hepatic artery mix in order for cells to remove useful substances
16
Q
Kupffer cells
A
Found in sinusoids
Breakdown and recycle old red blood cells
17
Q
Hepatic vein
A
Deoxygenated blood from liver to vena cava
18
Q
Bile canaliculus
A
Thin tube that collects bile secreted by hepatocytes
19
Q
Ornithine cycle
A
series of biochemical reactions that convert ammonia to urea
20
Q
Nephron
A
functional unit of the kidney
21
Q
Ultrafiltration
A
Filtration of the blood at a molecular level under pressure
22
Q
Antidiuretic hormone (ADH)
A
Hormone that controls the permeability of the collecting duct walls
23
Q
Osmoreceptor
A
Sensory receptor that detects changes in water potential
24
Q
Glomerular filtration rate (GFR)
A
Rate at which fluid enters the nephrons
25
Monoclonal antibodies
Antibodies made from one type of cell - they are specific to one complementary molecule
26
Renal dialysis
A mechanism used to artificially regulate the concentrations of solutes in the blood
27
Pacinian corpuscle
Pressure sensor in skin
28
Sensory receptor
Cells/sensory nerve endings that respond to a stimulus in the internal or external environment of an organism and can create action potentials
29
Transducer
A cell that converts one form of energy into another - in this case to an electrical impulse
30
Motor neurones
Neurones that carry an action potential from the CNS to the effector
31
Myelinated neurone
Has an individual layer of myelin around it
32
Non-melinated neurone
No individual layer of myelin
33
Relay neurones
Join sensory neurone to motor neurones
34
Sensory neurones
Neurones that carry an action potential from the sensory receptor to the CNS
35
Action potential
A brief reversal of the potential across the membrane of a neurone causing a peak of 40+mV compared to the resting potential of -60mV
36
Resting potential
The potential difference across the membrane while the neurone is at rest
37
Cholinergic synapse
Synapse that uses acetylcholine as its neurotransmitter
38
Neurotransmitter
Chemical used as a signalling molecule between two neurones in a synapse
39
Summation
Occurs when the effects of several excitatory post-synaptic potentials (EPSPs) are added together
40
Endocrine system
Communication system using hormones as a signalling molecule
41
Hormones
Molecules released by endocrine glands directly into the blood
Ast as messengers carrying signals to specific target organs/tissues
42
Target cells
Cells that have a specific receptor on their plasma membrane that is a complementary shape to the shape of the hormone molecule
43
Adrenal cortex
Outer layer of the adrenal gland
| Releases cortisol
44
Adrenal gland
Pari of glands above the kidneys
45
Adrenal Medulla
Inner layer of adrenal gland
| Releases adrenaline
46
Adrenaline
Hormone released from the adrenal glands, which stimulate the body to prepare for fight or flight
47
Beta cells
Found in Islets of Langerhans
| Secrete insulin hormone
48
Glucagon
Hormone that causes increase in blood glucose concentration
Glycolysis
Gluconeogenesis
49
Insulin
Hormone released from beta cells in pancreas
Cause decrease of blood glucose levels
Glycogenesis
50
Alpha cells
Found in Islets of Langerhans
| Secrete glucagon hormone
51
Hypoglycaemia
Blood glucose concentrations drop below 4mmol dm3- for long periods of time
52
Hyperglycaemia
Blood glucose concentrations too high for long periods of time
53
Diabetes mellitus
Condition where blood glucose concentrations can not be controlled effectively
54
Stem cells
Unspecialised cells that have the potential to develop into any type of cell
55
Abiotic components
Components of an ecosystem that are nonliving
56
Alkaloids
Organic nitrogen-containing bases that have important physiological effects on animals
.nicotine
.morphine
.quinine
57
Biotic components
Components of an ecosystem that are living
58
Pheromone
Any chemical substance released by one living things which influences the behaviour or physiology of another living thing
59
Tannins
Phenolic compounds located in cell vacuoles or in surface wax on plants
60
Tropism
Directional growth response in which the direction of the response is determined by the direction of the external stimulus
61
Apical dominance
Inhibition of lateral buds further down the shoot by chemicals produced by the apical bud at the tip of the plant shoot
62
Auxins
Plant hormones which are responsible for regulating plant growth
63
Gibberellins
Plant hormones which are responsible for the control of the stem elongation and seed germination
64
Geotropism
Directional growth response to gravity
65
Phototropism
Directional growth response to light
66
Autonomic nervous system
part of the nervous system responsible for controlling the involuntary motor activities of the body
67
Central nervous system
Brain
| Spinal cord
68
Peripheral nervous system
Sensory and motor nerves connecting the sensory receptors and effectors to the CNS
69
Somatic nervous system
Motor neurones under conscious control
70
Cerebellum
Region of the brain coordinating balance and fine control of movement
71
Cerebrum
Region of the brain dealing with higher functions such as conscious though
Divided into two cerebral hemispheres
72
Hypothalamus
Part of the brain that coordinates homeostatic responses
73
Medulla oblongata
Region of the brain that coordinates homeostatic responses
74
Pituitary gland
. Endocrine gland at base of brain
. Anterior lobe secretes many hormones
. Posterior lobe stores and releases hormones mode in the hypothalamus
75
Knee jerk reflex
Reflex action which straightens the leg when the tendon below the knew cap is trapped
76
Reflex action
Response that does not involve processing by the brain
77
Adenyl cyclase
Intracellular enzyme which is activated by certain hormones
78
Cyclic AMP (cAMP)
Secondary messenger released inside cells to activate a response
79
Cardiac muscle
Muscle found in the heart wall
80
Involuntary muscle
Smooth muscle that contracts without conscious control
81
Neuromuscular junction
Structure at which a nerve meets the muscle
| Similar in action to a synapse
82
Skeletal muscle (striated)
Muscle under voluntary control
83
Creatine phosphate
A compound in muscle that acts as a store of phosphates and can supple phosphates to make ATP rapidly
84
Granum (grana pl)
Inner part of chloroplasts made of stacks of thylakoid membranes where the light dependent stage of photosynthesis is takes place
85
Photosynthetic pigment
Pigment that absorbs specific wavelengths of light and traps the energy associated with the light
. Chlorophyll a and b
. Carotene
. Xanthophyll
86
Photosystem
System of photosynthetic pigments found in thylakoids of chloroplasts
. Traps protons and passes energy to primary pigment (Chlorophyll a)
. During light-dependent stage
87
Stroma
Fluid filled matrix of chloroplasts where light-independant of photosynthesis takes place
88
Thylakoid
Flattened membrane bound sac found inside chloroplasts
contain photosynthetic pigments
Site of light-dependant stage
89
Electron carriers
. Molecules that accept one or more electrons and donate them to another carrier
. Proteins embedded in thylakoid membranes
. Form electron transport chain
. NAD and NADP are electron carriers
90
NADP
Nicotinamide adenine dinucleotide phosphate
| Coenzyme and electron and hydrogen carrier
91
Photophosphorylation
Generation of ATP from ADP and inorganic phosphate in the presence of light
92
GP
intermediate compound in Calvin Cycle
93
RuBP
. Five-carbon compound present in chloroplasts
| . Carbon dioxide acceptor
94
TP
. Three-carbon compound
. Product of the calvin cycle
. Used to make other larger organic molecules
95
Water stress
Condition experienced by a plant when water supply becomes limiting
96
Glycolysis
First stage of respiration
10 stage metabolic pathway
Glucose converted to pyruvate
97
Cristae
Inner highly folded mitochondrial membrane
98
Mitochondrial matrix
Fluid filled inner part of mitochondria
99
Decarboxylation
Removal of carboxyl group from substrate molecule
100
Dehydrogenase
Removal of hydrogen atoms from a substrate molecule
101
Substrate-level phosphorylation
Production of ATP from ADP and Pi during glycolysis and the krebs cycle
102
Chemiosmosis
Flow of protons down concentration gradient across a membrane through a channel associated with ATP synthase
103
Oxidative phosphorylation
Formation of ATP using energy released in electron transport chain and in the presence of oxygen
Last stage in aerobic respiration
104
Respiratory substrate
Organic substrate that can be oxidised by respiration
| Energy release to make ATP molecules
105
Spatial summation
signals from multiple stimuli coordinated into single response
106
Temporal summation
2 or more nerve impulses arrive in quick succession from same presynaptic neurone.
makes action potentials more likely as more neurotransmitter released.
