Paper 1 and 3: Mass Transport Flashcards
1
Q
Cardiac output =
A
Stroke rate x volume
2
Q
Right side of heart =
A
Deoxygenated blood
3
Q
Left side of the heart =
A
Oxygenated blood
4
Q
How do you know which side is the left side of the heart on a diagram?
A
The one with the thicker muscle/ bigger side
5
Q
What direction do arteries carry blood?
A
Away from heart
6
Q
What direction do veins carry blood?
A
Towards the heart
7
Q
Why is the muscle on the left ventricle thicker than the right ventricle?
A
Cus it has more muscle/ muscle fibre
8
Q
Why are the ventricle walls thicker than the atria?
A
Cus they contract the heart w/ greater force = higher pressure to pump blood further
9
Q
What is the purpose of valves?
A
Prevent backflow of blood
10
Q
What is the exception to the artery rule?
A
Coronary arteries
11
Q
What do the coronary arteries do?
A
Supply oxygen & glucose to heart/ cardiac muscle
12
Q
What are factors that can lead to Coronary Heart disease (CHD)? [5]:
A
- Diet high in cholesterol
- Genetic factors
- Obesity
- Smoking
- high blood pressure
13
Q
What causes a heart attack (CHD)? [5]:
A
- CHD = narrower lumen in arteries
- Restricted blood flow so not enough reaches heart
- Not enough O2 and glucose so no ae respiration
- No ATP produced so no energy for heart to contract
- Mycordial infarction (heart attack)
14
Q
What is the name of the valve between the ventricles and arteries?
A
Semilunar valves
15
Q
What is the name of the valve between the atria & the ventricles?
A
Atrioventricular valves
16
Q
What are the other names for AV valves? [2]:
A
- Tricuspid valve
- Bicuspid valve
17
Q
What holds valves together so that they don’t invert?
A
Cords/ heart strings / tendons
18
Q
What does the hepatic artery do?
A
Carries blood away from heart towards liver
19
Q
What does the hepatic vein do?
A
Carries blood towards heart from liver
20
Q
What does the renal artery do?
A
Carries blood away from the heart towards the kidney
21
Q
What does the renal vein do?
A
Carries blood towards heart from kidney
22
Q
What are the stages of the cardiac cycle? [3]:
A
- Atria contract & ventricles relax
- Ventricles contract & atria relax
- Ventricles & atria both relax
23
Q
Cardiac cycle- stage 1 [4]:
A
- Volume of atria decreases
- so pressure in atria increases pushin blood to ventricles
- volume of ventricles increases
- So pressure in ventricles increases
24
Q
Cardiac cycle- stage 2 [4]:
A
- Increased vol in ventricles increases pressure
- AV valves close cus pressure in ventricles higher than in atria
- Blood pumped into aorta & pulmonary artery cus SL valves forced open
- This is cus pressure is lower in aorta & pulmonary artery
25
Cardiac cycle- stage 3 [3]:
- Blood flows thru aorta/ pulmonary artery
- Pressure in arteries increases = greater than ventricles
- Semilunar valves close
26
Why is the oxygen dissociation curve s- shaped/ sigmoid curve?
- First oxygen binds easily
- Makes it easier for 2nd & 3rd oxygen to bind
- Difficult for 4th Oxygen to bind
27
What type of biological molecule is haemoglobin? [2]:
- Quaternary protein
| - It has 4 polypeptide chains
28
Why is Hb a quaternary protein?
It has 4 polypeptide chains ( more than one)
29
Partial pressure of oxygen =
pO₂
30
High pO₂ =
High O₂ conc
31
Where is the pO₂ High?
At the alveoli
32
Where is the pO₂ low?
At respiring muscles
33
When does Hb have a high affinity for O₂?
When pO₂ is high
34
What happens with pO₂ at muscles? [4]:
- At respiring muscles pO₂ is low
- cus O₂ is continually diffused into muscle
- for aerobic respiration
- so Hb would have a low affinity for O₂ here
35
What happens to the pO₂ when pCO₂is high? [3]:
- when pCO₂ is high pO₂ is low
- Cus O₂ is being used for respiration which makes CO₂
- Oxygen dissociates more readily
36
When pO₂ is low =
Oxygen dissociates more readily from haemoglobin
37
Bohr shift [2]:
- At high pCO₂ Hb has a lower affinity for O₂ so O₂ dissociates readily
- The oxygen dissociation curve shifts to the right
38
What happens to glucose before translocation?
It is converted into sucrose
39
Why is glucose converted before translocation?
Cus sucrose is less soluble than glucose
40
Translocation [4]:
- sucrose AT'd into sieve tube elements at top of phloem
↓ Ψ
- Water from xylem osmosis into sieve tube element ↑ pressure at top of phloem
- Sucrose diffuses out from phloem into sink so Ψ at the bottom of phloem ↑
- Water osmosisises back into the xylem so pressure at the bottom of phloem ↓
- Sucrose in sink converted back into glucose so pressure gradient is established
41
What does a pressure gradient in the phloem mean? [4]:
- High pressure at the top
- Low pressure at the bottom
- Particles move from ↑ pressure to ↓ low pressure
- This allows for translocation to keep happening
42
How is starch digested? [3]:
- Amylase from saliva breaks down glycosidic bonds in starch (hydrolysing into maltose)
- Maltase hydrolyses glycosidic bonds into 2 a glucose
- Glucose cotransported with Na+
43
Where is amylase produced?
Salivary glands & mouth
44
Where is maltase produced?
Small intestine
45
Digestion of lipids [3]:
- Big lipid droplets are emulsified into bile salts (small drop)
- bile salts hydrolised by lipase into micelles
- micelles are fat soluble so can diffuse across membranes
46
Lipid droplets vs bile salts =
Bile salts have higher SA:Vol
47
what is a micelle?
Tiny droplets of monoglyceride + fatty acids that release the monoglyceride close to the cell membrane so that it can diffuse into the epithelium of the smol intestine
48
Digestion [definition]:
Hydrolysing large biological molecules, using enzymes, to small molecules that can be absorbed across cell mebrane
49
endopeptidases =
Hydrolyses peptide bonds within a polypeptide
50
Exopeptidases =
Hydrolyses peptide bonds at the END of the polypeptide
51
Membrane-bound dipeptidases =
hydrolyses the peptide bonds between dipeptides
52
Amino acid absorption [3]:
- Na+ pumped out into cell (low conc)
- It diffuses in via a co-transporter
- amino acids come in against their conc gradient
53
Veins [4]:
- Thin layer of muscle so can't contract
- smooth endothelium to reduce friction
- One way valves prevents backflow
- Low pressure blood
54
Arteries [3]:
- Narrower lumen than in vein so high-pressure blood
- Thick layer of muscle so can contract & change flow
- Folded endothelium & elastic tissue so they can recoil to maintain smooth pressure
55
Capillaries [3]:
- They surround all cells
- endothelium is 1 cell thick for short diffusion pathway
- Capillary beds have a high SA
56
Formation of tissue fluid [4]:
- Higher hydrostatic pressure in the blood than in tissues fluid
- so water & smol molecules forced out e.g glucose na+
- Large molecules stay in capillary
- Pressure decreases cus water leaves
57
Return of tissue fluid [4]:
- Ψ of blood lower than in tissue fluid cus proteins stayed
- so water moves into capillary thru osmosis
- causes excess tissue fluid to drain into lymph
- hydrostatic pressure drops in capillary (water moves down Ψ conc gradient
58
Transpiration [definition]:
The evaporation of water from the leaves thru the stomata
59
why is water cohesive?
Water molecules stick together cus they are polar
60
Xylem [4]:
- transports water & minerals
- upwards direction only
- hollow cus made of dead cells
= no cell wall
61
Cohesion tension theory [4]:
- Transpiration of water creates low pressure at the top of the xylem
- water in xylem is pulled up creating tension
- cus h2o molecules stick together so their weight can be supported in the column
- water molecules are sucked up to the leaves
62
Factors that affect transpiration [3]:
- Light
- humidity/ wind
- temp
63
How does light affect transpiration? [2]:
- More light = more stomata open
| - This means more waterloss/ evaporation
64
How does humidity/ wind affect transpiration?
They affect the water vapour gradient by decreasing it (not steep)
65
How does temp affect transpiration? [2]:
- more temp = more evaporation
| = more water puled up xylem
