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Biology - Unit 5 Flashcards

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0
Q

What two sources of evidence have led to our understanding of how the brain works?

A

Animal studies and studying human brains

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1
Q

How have brain diseases increased understanding of the brain?

A

What effect damage to different parts of the brain have

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2
Q

How are animals used for brain studies?

A

Effect if removing parts of the brain
Effect of artificially stimulating part of the brain
How the brain develops

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3
Q

What does the frontal lobe do?

A

Emotions
Speech
Decision making
Rational thought

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4
Q

What does the cerebrum do?

A

Integrates impulses in

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5
Q

Function of the parietal lobe

A 
Memory and recognition
Calculation
Movement
Sensation
Orientation
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6
Q

Occipital lobe function

A

Eyesight

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7
Q

Temporal lobes function

A 
Language
Hearing
Smell
Auditory information
Memory
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8
Q

Hypothalamus function

A

Homeostasis

Autonomic nervous system control

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9
Q

Pituitary gland function

A

Keeping water balance by releasing diuretics

Releases hormones like LH and FSH

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10
Q

Basal ganglia function

A

Motor control

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11
Q

Corpus callosum function

A

Connects the two hemispheres

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12
Q

Cerebellum function

A

Body control
Motor memory
Posture and balance

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13
Q

Medulla oblongata function

A

Breathing
Heart rate
Digestion
Sorts information

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14
Q

Olfactory bulb function

A

Sense of smell

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15
Q

Brain stem function

A

Joins to the spinal cord

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16
Q

How do CAT scans work?

A

Thousands of small X-ray beams passed through
Beam attenuated by tissue density
Data put together

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17
Q

What does attenuated mean?

A

Reduced in strength

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18
Q

How does MRI work?

A

Magnetic fields and radio waves passed through

Different tissues respond differently

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19
Q

How do fMRI scans work?

A

Monitors uptake of oxygen as deoxyhaemoglobin absorbs signal

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20
Q

Advantages of fMRI

A

Constant picture

Can see movement of oxygen

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21
Q

How do ultrasound scans work?

A

High frequency sound waves

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22
Q

How do X-rays scans work?

A

X-rays passed through body

Dense matter reflects them

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23
Q

What experiment did Crowley and Katz perform?

A

Injected newborn ferrets with radioactive tracers

Tracers moved from one eye and found in specific bands in visual cortex

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24
Conclusions of Crowley and Katz experiments
Neurones ordered in ocular dominance columns from birth
25
Experiments of Horton and Hocking
Prematurely delivered three monkeys Kept in dark with radioactive tracer in eye Found fully developed ocular tracers by time would have normally born
26
Horton and Hocking conclusions
Ocular dominance columns formed before birth | Visual cortex development due to genetic factors initially
27
Experiments of Hubel and Weisel on kittens and monkeys
Stitched shut one or both of animals eyes at different ages and for different lengths of time
28
Hubel and Weisel findings
Shut one eye at one week old and uncovered eye worked fine - swap eyes after a few months and animal could not see If did same at 4 months old, no effect
29
Findings by Hubel and Weisel
Critical windows of development
30
What are critical windows of development?
Periods of time during which vital connections are made in the brain in response to specific stimuli
31
Visual cortex development
Initially, dendrites for both eyes overlap If both eyes used as much, columns form of equal size for each eye (No overlap) If one eye used more, its columns are larger
32
What has been found from studying newborn babies brains?
There is discrimination towards paying more attention to biological movement than non-biological The younger you are the better your face recognition is Severe sensory deprivation can cause improper brain development
33
Polks research shows
Brain patterns more similar in identical twins than non for face/place recognition Little difference with regards to word and letter response
34
Work of Polk
Presented fraternal and identical twins with various scrambled images including letters and faces
35
What is species-characteristic behaviour?
Innate behaviour Seen in every member of a species Not learned
36
What is individual-characteristic behaviour?
Learned behaviour | Singular members who learn from experience
37
What is habituation?
Animal starts ignoring repeated stimulus as no punishment nor reward Gills of animal stop retreating when touched
38
What are conditioned reflexes?
Learning to associate new stimuli with an existing unconditioned reflex Pavlov's dogs
39
What is trial-and-error (operant) learning?
When an animal learns to associate a piece of trial behaviour with a reward or punishment so repeat or not
40
What is imprinting?
Young animal identifies with another organism and follows it around and relates to other similar objects
41
What is exploratory (latent) learning?
Animal explores new surroundings and learns them without any reward or punishment
42
What is insight learning?
Based on thought and reasoning | Once problem solved, the solution is remembered
43
How can habituation be shown using a land snail?
Poke it and its antennae withdraw | Takes less time to take them out again as the number of pokes increase
44
What is the cause of Parkinson's?
Nerve cells which produce dopamine die so movement slows as dopamine allows messages to be sent to the brain
45
What are the risk factors of Parkinson's?
``` Genetics Toxins Herbicides Head trauma Stroke Age ```
46
Why is Parkinson's difficult to treat?
We do not know the risk factors or what causes the dopamine-producing cells to die
47
What are the symptoms of Parkinson's?
Main symptoms: Tremors Slow movement Stiff and inflexible muscles Others: Fatigue Dementia Depression
48
How does L-Dopa work to treat Parkinson's?
It is converted into dopamine in the brain so more dopamine will be produced
49
What are the benefits of L-Dopa being used to treat Parkinson's?
Greatly relieves stiffness and slowness of movements Can be combined with carbidopa to improve action and reduce side-effects
50
What are the problems with using L-Dopa to treat Parkinson's?
Less effective after 4-5 years as brain cells continue to die Side effects: Dyskinesia- muscle spasms Low blood pressure Arrhythmia
51
How do dopamine agonists act to treat Parkinson's?
Bind to dopamine receptors in brain synapses and mimic action of dopamine
52
What are the benefits of using dopamine agonists to treat Parkinson's?
Last longer in the brain than L-Dopa | Effectiveness does not wane over time
53
What are the problems with using dopamine agonists to treat Parkinson's?
Not as effective as L-Dopa Cause similar side-effects to L-Dopa Can cause problems in controlling impulsive and compulsive behaviour
54
How do MAOB inhibitors work?
Block the action of MAOB which breaks down dopamine
55
What are the benefits of MAOB inhibitors?
Slows loss of dopamine | Can be used to make L-Dopa last longer or reduce amount needed
56
What are the problems with MAOB inhibitors?
When combined with L-dopa: Dyskinesia Hallucinations On own: Headache Depression Aching joints
57
What are the psychological symptoms of clinical depression?
``` Continuous low mood Feeling hopeless Low self-esteem Guilt ridden Irritable Anxiety ```
58
What are the physical symptoms of clinical depression?
``` Slow speaking or slow movement Change in appetite/weight (Usually decreased) Constipation Unexplained aches and pains Loss of libido Disturbed Sleep ```
59
What is the neurotransmitter involved in depression?
Serotonin
60
What is the role of serotonin in Depression?
Low levels result in fewer impulses so reduced brain activity. Low levels related to depression
61
What are the treatments for Depression?
``` Talking therapies Antidepressant drugs: -SSRIs inhibit re-uptake proteins -TCAs increase levels of serotonin -MAO inhibitors prevent neurotransmitter breakdown Ecstasy ```
62
What are the effects of Prozac at synapses?
Inhibits re-uptake proteins More serotonin in synaptic cleft More impulses travel Symptoms reduced
63
What is the effect of ecstasy on the concentration of serotonin in the synaptic cleft?
Greater concentration as the re-uptake proteins are inhibited
64
How does ecstasy work to inhibit the re-uptake proteins?
Similar shape to serotonin so blocks them off
65
Why does taking ecstasy produce a high?
More serotonin in the synaptic cleft Limbic system stimulated more Feeling of reward
66
What is pharmacogenomics?
The study of how a persons genetics affect their response to drugs
67
What is the purpose of pharmacogenomics?
Can tailor drugs to specific peoples genes so that it has maximum effect and minimum side-effects
68
What are the responses to drugs?
Full response - Beneficial and non-toxic Partial response - Beneficial but toxic Non responsive - Not beneficial but non-toxic Severe adverse reaction - Toxic and not beneficial
69
What factors influence drug response?
``` Gender Age Weight Diet Genetics Co-medication Environmental agents (E.g. Smoking) Disease ```
70
How important are genetics in drug response?
Account for between 20-95% of variation in response
71
What are the stages of drug action in the body?
``` Absorption Distribution Target interaction Metabolism Excretion ```
72
What are the two main gene groups involved in drug response?
Pharmacokinetic - Affects how the drug is handled by the body (E.g. Drug metabolising enzymes) Pharmacodynamic - The drugs effect on the body (E.g. Receptors)
73
What are SNPs?
Single nucleotide polymorphisms Genetic variants that affect a drugs action Haplotypes - Combinations of related SNPs
74
How is pharmacogenomics enhancing the treatment of cancers?
Drugs that target the genetics of cancer cells to reduce toxicity and increase efficacy
75
How does Herceptin act to combat cancers?
Targets the chemical which causes massive growth Block growth factors Targets Her2 proteins on cancer cells
76
Why is Herceptin not perceived to be truly based on pharmacogenetics?
Targeted for tumour cells genetics not persons genome
77
What is efficacy?
Maximum beneficial response a drug can produce | % of recipients who show a therapeutic response at a given dose
78
What is toxicity?
The extent to which a drug has adverse side effects | % of recipients who show adverse side effects
79
What is the optimal dose range of a drug?
That at which efficacy is greatest and toxicity lowest
80
Why will pharmacogenomics not replace proper clinical management?
Need to choose best drug based on other factors as well
81
What are the benefits of tailoring drugs?
More effective Lower dosage needed Less side-effects
82
Where can pharmacogenomics save lives?
Minimising deaths due to severe adverse reactions
83
Why are microbes frequently used in genetic engineering?
Easy and cheap to culture Reproduce rapidly Easily identified
84
How do scientists know which microbes have taken up new genes?
Incorporate antibiotic resistance into new genes | Only ones with new genes survive antibiotics
85
What were the problems with previous methods of getting insulin?
Got from animals - Immune system attacked the insulin - Supply relied on animals being slaughtered
86
What is humulin?
Pure human insulin produced by bacteria
87
How is humulin produced?
One of each of the two polypeptide chains inserted into two bacteria using vectors
88
How is proinsulin production different to humulin production?
Only requires one type of bacteria while humulin requires two
89
What is the problem with using prokaryotes for drugs?
Cannot make complex human proteins
90
What is the use of bananas in GMOs?
Bananas are being developed which contain vaccines or vitamins
91
What is a crown gall?
A tumour which appears on a plant
92
What is the use of crown galls in transgenic plant technology?
It forms on the plant and can be taken and cultured and used to produce new plants containing the genes
93
What is the method of transgenic plant creation?
Ti plasmid removed from A. Tumefaciens bacterium Gene to be carried inserted into plasmid Plasmid returned to bacterium Bacterium inserted into plant Crown gall develops on plant which can be taken and cultured
94
What is a tropism?
A growth in response to stimulation
95
What are the stages of plant growth through mitosis?
``` Division - Mitosis Assimilation - New material brought in Elongation - Vacuoles develop -Cellulose wall stretches -Large central vacuole forms ```
96
Where does the most plant growth occur?
At the meristems (Just behind stem and root tips)
97
What are short-day plants?
Plants that flower when nights are long and days are short
98
What are long-day plants?
Plants that flower when nights are short and days are long
99
What is photoperiodism?
A plants ability to flower in response to changes in the photoperiod (Relative lengths of day and night)
100
What are day-neutral plants?
Plants whose flowering is unaffected by the lengths of the day and night
101
What is the environmental cue for flowering?
Length of darkness
102
What was the work by Hamner and Bonner with regard to critical periods?
Long-day plant can flower if in a short day, the long night is interrupted by a flash of light
103
What are the effects of red light on plant germination?
Inhibits short-day Stimulates Long-day Stimulates seed germination
104
What are the effects of far-red light on plant germination?
Inhibits seed germination Inhibits long-day Stimulates short-day
105
What is the photosensitive pigment involved in plant germination?
Phytochrome
106
How is Pfr converted into Pr?
Darkness - Slow conversion | Far-red light - Rapid conversion
107
How is Pr (P660) converted into Pfr (P730)?
Daylight White light Red light
108
What is etiolation?
Rapid growth in an attempt to reach light
109
What is the effect of Pr build-up/darkness on plant growth?
``` Tall and thin Small, pale leaves Long internodes Fragile stems Little chlorphyll ```
110
What is the effect of Pfr build-up on plant growth?
``` Green leaves Chlorophyll formation Thick Strong stem Shorter internodes ```
112
What did the experiments which proved the existence of florigen involve and show?
All but one leaf covered, entire plant flowers - Chemical produced which travels across plants Only flowers if exposed leaf left in place for time - Takes time to synthesise chemical and travel it Flowers if light-induced plant grafted on - Moves from leaf into plant
113
What were the experiments which proved the existence of auxin?
``` Darwin: -Covering apex -Removing apex Boysen-Jenson: -Effect of inserting mica barrier unilaterally Paal: -Tip replaced off-centre Went: -Tip incubated on gelatin block. Block replaced off-centre ```
114
What is IAA?
The first auxin discovered
115
What is an auxin?
The growth substance involved in phototropisms
116
How are neurones adapted for their function?
Long and thin - Take up little space but reach where needed Not bound to other neurones - Can make and break connections Flexible - Make connections easily Chemical messengers to cross synapses
117
What is the difference between an axon and a dendron?
Axons carry impulses away from the nerve cell body while dendrons carry them towards it.
118
What is the structure of a motor neurone?
Cell body with dendrites Axon Synaptic bulbs Effector
119
What is the structure of a sensory neurone?
``` Receptor Dendrites Dendron Connection to Cell body Axon Synaptic bulbs ```
120
What is the structure of a relay neurone?
``` Dendrites Dendron Cell Body Axon Synaptic bulbs ```
121
What is the structure of a myelin sheath?
Schwann cell wrapped around axon multiple times Cytoplasm and nucleus on outside Node of Ranvier between adjacent ones
122
Why are myelin sheaths important?
Protect nerves from damage | Speed up transmission of nerve impulse
123
What was the method used to discover how neurones work?
Took giant squid axons Electrode filled with conducting solution inserted Electrode attached with wire to amplifier Two electrodes, one inside axon and one outside detect voltage Difference amplified and displayed
124
What is the resting potential of an axon?
-70mV
125
How is the resting potential of an axon maintained?
Na+/K+ pump creates concentration gradient | K+ channel allows diffusion out
126
What is the action potential of an axon?
+40mV
127
How is an action potential formed?
Na+ channels open | K+ channels close
128
What are the stages of the refractory period?
Absolute refractory period - Impossible to re-stimulate | Relative refractory period - Threshold has been raised
129
What is an axons refractory period?
Its recovery time following an action potential
130
How is an action potential conducted along a nerve fibre?
The change in potential difference in one section due to the action potential causes a change in potential difference and therefore an action potential in the adjacent section
131
What is saltatory conduction?
The jumping of a nerve impulse from node to node along a myelinated nerve fibre
132
How are impulses transmitted across synapses?
``` Calcium ions flow in Vesicles fuse to pre-synaptic membrane Neurotransmitter (Acetylcholine) released into synaptic cleft Neurotransmitter fuses to receptors Na+ flows in EPSP or IPSP set up Cholinesterase breaks down acetylcholine Acetylcholine re-absorbed ```
133
What is an EPSP and IPSP?
EPSP (Excitatory post-synaptic potential) - Inside of post-synaptic membrane becomes more positive than resting potential IPSP (Inhibitory post-synaptic potential) - Inside of post-synaptic membrane becomes more negative than resting potential
134
What is spatial summation?
Multiple action potentials arrive at a synapse at once
135
What is temporal summation?
Two action potentials from the same fibre arrive slightly after one another
136
What is facilitation?
Where multiple small impulses add together to create a larger one which can overcome the threshold
137
What is accommodation?
When neurones stop responding to a repeated stimulus
138
What is a primary receptor?
A dendrite
139
What is a secondary receptor?
A specialised cell which synapses with a sensory neurone
140
What is an exteroreceptor?
A receptor which responds to stimuli from outside the body
141
What is an interoreceptor?
A receptor which responds to stimuli from inside the body
142
What law do generator potentials not obey?
The all-or-nothing law
143
What current and potential are set up in receptors?
Generator current and generator potential
144
What is convergence?
Where several generator potentials summate and trigger an action potential
145
What is adaptation of receptors?
Where a receptor is exposed to a steady stimulus so there is a decline in generator potentials
146
What is the function of the ciliary muscles?
Change the shape of the lens
147
What is the function of the conjunctiva?
Lubricates eye | Prevents entrance of microbes
148
What is the function of the suspensory ligament?
Supports eye | Prevents downward displacement
149
What is the function of the vitreous humour?
Maintains the eye shape
150
What is the function of the sclera?
Protects the eye
151
What is the function of the retina?
Produces images
152
What is the function of the fovea?
Causes sharper vision | Area with only rod cells
153
What is the function of the optic nerve?
Carries impulses to brain from retina
154
What is the blind spot of the eye?
Area of no photoreceptor cells
155
What is the function of the lens?
Focuses light onto the retina
156
What is the function of the iris?
Muscles which can change size of the pupil | Pigment gives eye its colour
157
What is the function of the pupil?
Allows light to enter (size can be changed)
158
What is the function of the cornea?
Helps focus light
159
What is the function of the aqueous humour?
Maintains pressure - protects eye | Helps focus
160
What type of receptors are the photoreceptors in the retina?
Secondary exteroreceptors
161
What are the two types of photoreceptors in the eye and what are their differences?
``` Rod cells: -More sensitive, -Show black and white and dim light -Show motion and peripheral -More of them -Convergence Cone cells: -Colour vision -Focus ```
162
What is the layout of the photoreceptors in relation to the retina?
Light sensitive part closest Mitochondria Synapse
163
What pigment do rod cells contain?
Rhodopsin
164
What happens to rhodopsin when bleached?
Splits into opsin and retinal Opsin allows sodium in Generator potential occurs
165
How is rhodopsin reformed from opsin and retinal?
Lack of light stimulation
166
What are light and dark adapted with regards to rhodopsin?
Light adapted - Rods bleached and can no longer respond to dim light Dark adapted - Rhodopsin reformed and eye sensitive to dim light
167
What pigment do cones contain?
Iodopsin
168
What are the main features of iodopsin?
Three types - each sensitive to one primary colour Needs more light energy to break down than rhodopsin Not sensitive to low light intensities Provides colour vision
169
What is the iris?
A muscular diaphragm with the pupil in the middle
170
Why does light only go through the pupil?
Pigments in the iris absorb the other light
171
How is amount of light into the eye controlled?
By pupil size - Circular and radial muscles
172
How is the pupil widened?
The radial muscles contract and circular relax
173
How will pupil size change when it is brighter?
Gets smaller
174
What is the mechanism for pupil size changing?
Light falls on retina sensory cells Impulses occur - More light=More action potentials Control centre in hindbrain detects it Nerve impulses synapse parasympathetic cranial nerve Iris effectors stimulated
175
What drugs cause change in pupil size?
Pilocarpine - Decreases it | Atropine and adrenaline - Widens it
176
What is another name for the iris' circular muscles?
Sphincter pupillae
177
What is another name for the iris' radial muscles?
Dilator pupillae
178
What does transgenic mean?
Taking genes from one organism and inserting into the DNA of another from a different species
179
What is the process of getting an animal to produce a human protein?
Copy of human gene and promoter sequence inserted into genetic material of different species' egg Egg fertilised and inserted into surrogate mother Baby born and grown to maturity Milk of animal with new gene harvested and purified Human protein extracted from milk
180
How are genes inserted into animals via microinjection?
DNA injected into cell by fine micropipette controlled my micromanipulator. Many cells injected before one takes up the DNA successfully
181
How are genes inserted into animals via microprojectiles?
DNA shot into cell at high speed carried by gold or tungsten pellets. Some cells survive and accept the DNA
182
How are genes inserted into animals via viruses?
Harmless viruses engineered to carry gene and used to infect animals cells
183
How are genes inserted into animals via liposome wrapping?
Gene wrapped in liposomes (spheres formed from lipid bilayer). Fuse to and pass through cell membrane to deliver DNA into cytoplasm
184
What are advantages to transgenic animals?
``` Disease treatments Alleviate suffering Continuous supply Avoids immune response and infection from human diseases Purer ```
185
What are disadvantages to transgenic animals?
Concerns about safety of animals and of humans who use the product Expensive to develop
186
Why are promoter sequence used with transgenic animals?
So that the gene is expressed in the mammary gland so present in the milk
187
What is striated muscle attached to?
The skeleton
188
What is striated muscle involved in?
Locomotion
189
Why is striated muscle called that?
It appears striped
190
What are muscle fibres made up of?
Parallel myofibrils
191
What are myofibrils made up of?
Sarcomeres
192
What is the myofibril cytoplasm called?
Sarcoplasm
193
What proteins make up sarcomeres?
Actin and myosin
194
What does the sarcoplasm contain?
Mitochondria
195
What is stored in the sarcoplasmic reticulum?
Calcium ions
196
What controls smooth muscle?
The involuntary nervous system
197
What is striated muscle also called?
Skeletal muscle or voluntary muscle
198
What is smooth muscle also called?
Involuntary muscle
199
Where is smooth muscle found?
In the gut and blood vessels
200
What is the stamina of striated muscle?
Contracts rapidly but fatigues quickly
201
What is the stamina of smooth muscle?
Contracts and fatigues slowly
202
Where is cardiac muscle found?
In the heart
203
What is myogenic?
Generates own contractions with impulses from self
204
What are the properties of cardiac muscle?
Striated and myogenic
205
What is the A band?
The width of a myosin filament
206
What is the H zone?
The gap between two adjacent myosin filaments
207
What is the Z line?
The line down the middle of an actin filament
208
What is the M line?
The line down the middle of a myosin filament
209
What is the I band?
The gap between two adjacent myosin filaments
210
What makes up an actin filament?
Actin, troponin and tropomyosin
211
What happens to the muscle fibre in contraction?
It gets shorter
212
What is summation?
Where multiple contractions are so close they give the appearance of a single larger contraction
213
What is tetanus?
Where the muscle fibre becomes fully contracted
214
What are slow twitch muscle fibres adapted for?
Steady action over a period of time
215
What is the stamina of slow twitch muscle fibres?
Slow contraction and long tetanus
216
What are slow twitch muscle fibres used for?
Maintaining body posture and long periods of activity
217
What do slow twitch muscle fibres contain?
A rich blood supply, lots of mitochondria and plenty of myoglobin
218
What is myoglobin?
A protein similar to haemoglobin which is made of one chain and has a higher oxygen affinity
219
What are slow twitch muscle fibres also called?
Oxidative or red muscle fibres
220
What do slow twitch muscle fibres use as fuel?
Glucose
221
What is the stamina of fast twitch muscle fibres?
Rapidly contract and fatigue quickly
222
What are fast twitch muscle fibres used for?
Sudden, rapid bursts of activity
223
What are fast twitch muscle fibres adapted to cope with?
Anaerobic conditions
224
What do fast twitch muscle fibres contain little of?
Few blood vessels, little myoglobin and a fairly small number of mitochondria
225
What do fast twitch muscle fibres contain lots of?
Glycogen and creatine phosphate
226
What is creatine phosphate used for?
Forming ATP
227
What are fast twitch muscle fibres also called?
Glycolytic or white muscle fibres
228
What is the theory for how muscle contraction occurs?
The sliding filament theory
229
What is the method of muscle contraction?
Calcium ions are released Troponin-tropomyosin complex rotates Actomyosin bridge formed ADP and phosphate detach from myosin head Myosin head rotates to shorten sarcomere ATP binds to head, breaking bridge and shortening sarcomere
230
What is bone made of?
Bone cells embedded in a matrix of collagen and calcium salts
231
What properties does bone have?
Strong and hard, resistant to compressive forces, light
232
What is cartilage made of?
Chrondocytes in a matrix of collagen fibrils
233
What are the two main types of cartilage?
Hyaline and white fibrous
234
What are the properties of cartilage?
Hard but flexible, elastic, good shock absorber
235
Where is cartilage found?
Between bones and in the joints
236
Where is hyaline cartilage found?
At the ends of bones
237
Where is white fibrous cartilage found?
Between the bones in the joints and it forms the intervertebral discs
238
What are tendons made of?
White fibrous tissue
239
What are tendons used for?
Joining muscles to bones
240
What are the properties of tendons?
Strong but inelastic
241
What do ligaments do?
Hold bones together and in the correct alignment
242
What are the properties of ligaments?
Elastic
243
What are ligaments made of?
Yellow elastic tissue
244
What is the liquid lubricant produced by joints called?
Synovial fluid
245
What are joints lined with?
A layer of replaceable rubbery cartilage
246
What does Glucose become in the initial step of Glycolysis?
A phosphorylated 6C sugar
247
What is formed in the initial step of glycolysis?
ADP and a phosphorylated 6C sugar
248
What does the phosphorylated 6C sugar split into in glycolysis?
2 3C phosphates
249
What is formed in anaerobic respiration in animals?
Lactic acid
250
What occurs when the 2 3C phosphates split into 2 pyruvates in glycolysis?
Reduced NAD and ATP are formed
251
What is formed in anaerobic respiration in bacteria and yeast?
Ethanol and CO2
252
How much ATP is produced in glycolysis?
8 molecules
253
What is the enzyme which regulates the rate of respiration?
Phosphofructokinase
254
How is pyruvate converted into acetyl CoA in respiration?
By turning NAD into reduced NAD and by forming CO2
255
What are the enzymes which remove CO2 in respiration?
Decarboxylases
256
What are the enzymes that remove hydrogen in respiration?
Dehydrogenases
257
How is Citrate formed from acetyl CoA in respiration?
By combining with a 4C acid
258
How does citrate become a 5C acid in the Kreb's cycle?
By producing CO2 and reduced NAD
259
What is produced in forming a 4C acid from the 5C acid in the Krebs cycle?
CO2, ATP, 2 reduced NADs and reduced FAD
260
What is oxidative phosphorylation?
Moving electrons down an electron transport chain down the energy levels, phosphorylating ADP and requiring oxygen
261
How many turns of the Krebs cycle are there per glucose molecule?
2
262
How many molecules of ATP are formed per molecule of reduced FAD?
2
263
How many molecules of ATP are formed per reduced NAD?
3
264
What is formed at the end of the electron transport chain?
A water molecule
265
Where does glycolysis take place?
In the cytoplasm
266
Where does the Krebs cycle take place?
Mitochondrion matrix
267
Where is ATP synthesised in respiration?
The cristae of the mitochondria
268
What theory says how ATP is produced?
The chemiosmotic theory of ATP production
269
What happens to the hydrogen ions left behind by the electrons in respiration?
They are actively transported into the space between the inner and outer membranes
270
What gradients are set up between the space and the matrix in respiration?
Concentration, pH and electrochemical
271
What happens when the protons travel across the membrane through the pores in respiration?
The ATPase enzyme linked to the stalked particles produces ATP
272
How much ATP is produced in respiration?
38 molecules
273
What are the electron acceptors involved in respiration?
Nicotinamide Adenine Dinucleotide (NAD)Flavine Adenine Dinucleotide (FAD)
274
How does electrical excitation spread through the heart?
Sinoatrial node sets up a wave of depolarisation Atria contracts Excitation spreads to atrioventricular node AVN excited and excitation passes to bundle of his Excitation to purkyne tissue Depolarisation travels down septum Ventricles contract
275
What is homeostasis?
The maintenance of a steady internal state in the body almost regardless of changes of conditions
276
What are negative feedback systems?
Systems which act to oppose a change in conditions
277
What is cardiac output?
Cardiac volume X heart rate
278
Where is the cardiovascular control centre?
In the medulla of the brain
279
What controls changes to heart rate?
The cardiovascular control centre
280
What does most of the nervous control of the heart?
The autonomic (involuntary) nervous system
281
What is the autonomic nervous system split into?
The sympathetic and parasympathetic systems
282
What does the sympathetic nervous system do to the heart rate?
Excites it
283
What does the parasympathetic system do to the heart rate?
Inhibits it
284
What does adrenaline do to the heart rate?
Increases it
285
Where are to hearts stretch receptors?
In the muscle walls
286
How do the stretch receptors register a need to increase the heart rate?
They register more blood returning as the muscles squeeze more blood along as they work
287
What do baroreceptors register?
Pressure
288
Where are the baroreceptors for heart rate found?
In the sinuses of the carotid arteries in the neck
289
How do the heart rates baroreceptors register a need to increase heart rate?
The blood vessels dilate as adrenaline is produced so blood pressure falls
290
What is tidal volume?
The volume of air entering and leaving the lungs in a normal resting breath
291
What is the inspiratory reserve volume?
The maximum air you can breath in after normal breathing
292
What is expiratory reserve volume?
The maximum volume of air that can be expelled after a normal expiration
293
What is vital capacity?
The total of the tidal volume, and inspiratory and expiratory reserves
294
What is the residual volume?
The volume left after the strongest possible expiration
295
What is the total lung capacity?
The sum of the vital capacity and the residual volume
296
What is the inspiratory capacity?
The tidal volume + the inspiratory reserve volume
297
What gives the stimulus to inhale and exhale?
The respiratory centre
298
What controls breathing in?
The inspiratory centre
299
What controls breathing out?
The expiratory centre
300
How does breathing occur?
Inhale Intercostal muscles and diaphragm contract Lungs inflate Stretch receptors in bronchi wall register Stop breathing in
301
What do chemoreceptors register in regards to breathing?
Register CO2 and pH levels
302
How do the chemoreceptors cause increased breath rate?
Increased CO2 levels pH and oxygen levels fall Chemoreceptors register changes Breathing increases
303
What is the control of temperature through homeostasis called?
Thermoregulation
304
How can temperature tolerance be measured?
Via a calorimeter
305
What is the low critical temperature?
The point below which the bodys thermoregulatory measures have no effect
306
What is the low lethal temperature?
Temperature below which chemical reactions stop in the body
307
What is the high critical temperature?
Temperature above which the bodys thermoregulatory measures have no effect
308
How do the superficial blood vessels cool the body down?
Vasodilation occurs Sphincter muscles relax More blood through superficial capillaries More heat loss by radiation and conduction
309
How do the superficial blood vessels warm the body up?
Vasoconstriction occurs Entrance to capillaries closes More blood through shunt vessel Less blood loss
310
What measures cool the body down?
Sweating More blood closer to skin Panting
311
What measure are used to warm the body?
Shivering Less blood close to skin Hairs stand up More adrenaline produced
312
Where are the heat gain and loss centres?
In the hypothalamus
313
Where are the warm and cold receptors?
In the skin and hypothalamus
314
What contributes to type two diabetes?
Obesity Lack of exercise Poor diet
315
What can too much exercise cause?
Weakened immune system Increased risk of upper respiratory tract infections Less T killer and helper cells Less B cells and phagocytes
316
What is arrhythmia?
Abnormal heart contraction rhythm
317
What is ischaemia?
Starvation of the heart of oxygen
318
What can be a heart disorder that is not registered by ECGs?
Ischaemia
319
What is atrial fibrillation?
An arrhythmia caused by the atria beating too fast and ineffectively
320
What can atrial fibrillation cause?
Increased risk of clots Stroke Inefficient heart pumping
321
What is tachycardia?
Where the heart beats too quickly so the ventricles have no time to empty Less of a period of no polarity Muscles and brain may be starved of oxygen
322
What is the P wave?
Depolarisation of the SAN and related tissue in the atrium
323
What is the T wave?
Rapid repolarisation of the Purkyne tissue in the ventricles
324
What is the QRS in an ECG?
Spread of excitation through the ventricles
325
What is ventricular fibrillation?
Ventricles contract erratically and weakly Little blood pumped out of arteries Small QRS Starved of blood - can cause heart attack
326
What is rheumatoid arthritis?
Immune cells attack membranes lining joints which produce synovial fluid
327
What can rheumatoid arthritis cause?
Joint swelling Stiffness Pain Inflammation in nearby tendons, muscles and ligaments
328
What is osteoarthritis?
Immune cells attack cartilage
329
What is thought to be the main causes of osteoarthritis?
Genetics and as a delayed response to injury
330
What is WADA?
World Anti Doping Agency
331
What do anabolic steroids do?
Builds muscle mass and increases speed
332
What does EPO do?
Increase red blood cell count and amount of oxygen in the blood
333
What do hormone agonists do?
Mask or change another hormones action
334
What do drug cheats use diuretics for?
Urinate more and so lose weight or remove evidence of illegal substances
335
Why do athletes blood transfuse?
Increase oxygen in blood
336
What is gene doping?
Attempting to change genes to enhance performance
337
What do stimulants do?
Increase heart rate and make you more alert
338
What are narcotics?
Painkillers
339
What do beta blockers do?
Make heart beat slower | Reduce effect of adrenaline Steadier
340
How do defibrillators work?
Depolarise a critical mass of the heart Terminate arrhythmia Allowing SAN to reestablish hearts rhythm
341
What do creatine supplements do?
Get more creatine phosphate to make ATP
342
What is the action of anabolic steroids?
Passes through cell membrane Binds to receptor molecule Carried into nucleus Hormone-receptor complex acts as a transcription factor Binds to DNA and switches on genes linked to protein synthesis Produced RNA changed
343
What are anabolic steroids linked to?
``` Infertility Impotence Liver damage High blood pressure Agression ```
344
What is the action of Erythropoietin?
Binds to receptor on cell membrane Activates second messenger Protein cascade set off Functional second messenger enters nucleus and acts as transcription factor Enzyme synthesis genes switched on or off
345
What is EPO linked to?
Strokes Heart attacks High blood pressure

Biology (5 decks)

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