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[OBSELETE] Edexcel - A Level Bio > Topic 1 > Flashcards

Topic 1 Flashcards

1
Q

What is mass transport?

A

Mass Transport - the bulk movement of gases or liquids in one direction via a system of vessels and tubes from one part of the organism to the other.

Mass transportation systems:

  • Xylem vessles
  • Blood systems in insects
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2
Q

What are the Limitations of Diffusion?

A

High SA:V (Unicellular Organism) = Diffusion ✔️

Low SA:V (Multicellular Organism) = Diffusion ❌

Multicellular Organism= high O$_2$ demand for respiration

(diffusion cant keep up)

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3
Q

What are the different types of Circulatory Systems

A

There are 3 types:

  • Open (Insects)
  • Single (Fish)
  • Double (Humans)
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4
Q

How does the open circulatory system work?

A

Features of a open circulatory system:

  • Blood not all in blood vessels
  • A simple heart contracts and pumps of blood through cavities
  • Blood surrounds the heart where substance can diffuse from the blood to the organs.
  • Simple heart then contracts and blood is draw back into small heart openings
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5
Q

How does the single circulatory system work?

A

Blood flows through heart once each circulation

Heart → arteries → gills → body tissue → veins → REPEAT

High pressure

Low Pressure

Gills especially because they are delicate

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6
Q

How does the double circulatory system work?

A

The right ventricle = deoxygenated blood

(From body to lung)

The left ventricle = oxygenated blood

(From lung to body)

Blood flows through heart twice → reducing time to circulate around body → increasing metabolic rate

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7
Q

What is a solvent?

A
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8
Q

What are arteries?

A

Arteries take blood away from the heart to the rest of the body

  • Thick muscular walls
  • Elastic tissue
  • Narrow lumen
  • Folded endothelium means artery expansion
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9
Q

What is the structure of Veins?

A

Veins take blood from the rest of the body to the heart

  • Thin muscle wall
  • Little elastic tissue
  • Wide lumen
  • Contains valves
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10
Q

What are the structure of capillaries?

A

Capillaries is where metabolic exchange occurs

  • One cell thick endothelium
    • Allows for faster and more efficient gas exchange
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11
Q

What is systole and diastole?

A

Diastole - Relaxing of the heart

(Dinosaur 🦖 )

Systole - Contraction of the heart

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12
Q

What are the stages of the cardiac cycle?

A

3 Stages (Atrial Systole, Ventricular Systole, Cardiac Diastole )

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13
Q

What happens in Atrial Systole?

A

Atrial Systole

  1. Blood Returns to heart
  2. Atriums low pressure → High pressure
  3. AV valve then opens letting blood into the ventricle
  4. Increasing ventricle pressure
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14
Q

What happens in ventriacle systole?

A

Ventricle Systole

  1. Ventricle contraction from the base upwards
  2. Ventricle Pressure increase
  3. SL Valves open moving blood to aorta/pulmonary artery
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15
Q

What happens in cardiac diastole?

A

Cardiac Diastole

  1. Atrium and ventricles then relax
  2. Elastic Recoil lowers pressure
  3. High pressure aorta /pulmonary artery close SL Valve
  4. Pressure difference between ventricle and atrium (AV Valves open)
  5. Meaning blood passively moves into the ventricle
  6. Atrium fills up from vena cava / pulmonary vein
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16
Q

How does pressure change during the cardiac cycle?

A
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17
Q

What is an Atheroma?

A

An atheroma is the material from buildup of lipids, macrophages and fibrous tissue

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18
Q

Exaplain this diagram

A

Endothelial Dysfunction

  • Damage to the endothelium lining from high blood pressure
  • Resulting in endothelial dysfunction
  • This leads to an inflammatory response

Inflammatory Response

  • Macrophages move to the effected area
  • Macrophages and lipids buildup forming fatty streaks

Plaque formation

  • More white blood cells, lipids and connective tissue buildup
  • Then hardens forming to form a fibrous plaque (Atheroma)
  • This partially blocks the lumen increasing blood pressure

Artery Hardening

  • The artery then hardens due to the swelling
  • THIS IS CALLED ATHERCELOROSIS
  • This can lead to blood clots and haemorrhages
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19
Q

Why do we need blood clotting?

A

Blood Clotting Purpose:

  • Ensures blood vessels don’t break
  • Bacterial and Viral protection
  • Prevents bleeding to death
20
Q

What is the general blood clotting process?

A
  1. Vasoconstriction - To reduce severity of trauma to endothelial cell
  2. Platelet Activation - Platelets sent to effected area creating platelet plug
  3. Blood clot formation - platelets, blood cells are trapped in meshwork(Meshwork stronger than temp platelet plug)
21
Q

What the process of making the blood clot?

A

Prothrombin to Thrombin

Damage to blood vessel = Thromboplastin released

Thromboplastin is a protein

Thromboplastin, Vitamin K and $Ca^+$

Prothrombin (Soluble protein) → thrombin (enzyme)

Fibrinogen to Fibrin

Thrombin catalyses conversion of fibrinogen (soluble protein) to fibrin (solid insoluble fibers)

These Fibrin monomers can polymerise to form fibrin fibers

Clot formation

  • Fibrin fibers then cross link to form a mesh
  • This mesh then collects blood cells and platelets
22
Q

What environmental risk factors are there for CVD?

A

Diet

  • High saturated fat = increased cholesterol level (increasing atheroma risk)
  • High salt = increased blood pressure (inflammatory response risk)

High Blood Pressure

Increasing blood pressure ⇒ damage to artery lining ⇒ atheroma formation

Smoking, High alcohol consumption and inactivity can lead to high blood pressure

Smoking

  • Carbon monoxide binds to haemoglobin decreasing oxygen in body which could lead to heart attacks or strokes
  • Nicotine makes platelets sticky increasing blood clot risk
  • Decreases antioxidants decreasing artery lining protection increasing risk of inflammatory response
23
Q

What genetic risk factors are there for CVD?

A

Genetics

Some people may inherit alleles which code for high blood pressure or high cholesterol level

Age

Risk of CVD increases with age as plaque can buildup over time leading to higher CVD risk

Gender

Males can’t produce oestrogen which increases HDL (Good cholesterol) which helps with removing LDL (Bad cholesterol) which would decrease blood cholesterol and blood pressure.

24
Q

What is correlation and causation?

A

Correlation - where there is a visible trend between two or more factors

Chance of 🦈 attacks increase when 🍨 sales are up

Causation - where two or more factors directly influence each other

Chance of 🦈 attacks increase when amount of 🫂 go to the beach

25
Q

How do you analyse and interpret data?

A
  1. Describe data
    1. Risk of breast cancer doesn’t change with any smoking
  2. Draw conclusions
    1. For women who don’t drink smoking doesn’t have an effect on risk of breast cancer (no correlation)
  3. Check for validity of conclusion
    1. Just because there is no correlation with just smoking maybe smoking and drinking has an effect
    2. Doesn’t take into account other factors like hormone replacement treatment and physical activity
26
Q

What factors influence study design?

A
  • BIG SAMPLE size means more data points (to increase representability)
  • AS MANY CONTROL VARIABLES the more variables controlled the better the reliability of the study of one variable
  • UNBAIS DATA COLLECTION the more viable the results and conclusions drawn form the data collected
  • REPETION this allows for the data collected to be valid and to be repeated by other scientists
27
Q

Why may people overestimate risk?

A

People may overestimate risk because

  • Anecdotal evidence (know people effected by CVD)
  • Exposure through media (headlines about CVD increase risk perception)
28
Q

Why may people underestimate risk?

A

People may underestimate risk because

  • Lack of information leading to lack of awareness
  • Lack of awareness to factors increase CVD
29
Q

What are energy budgets?

A

The amount of energy taken in by eating vs the amount of energy used up

30
Q

What is energy balance and what happens if its unbalanced?

A

Energy taken in = Energy Used

If unbalanced then the persons weight would be effected

Weight gain = input > output

Weight loss = input < output

Some energy is required to maintain body processes

31
Q

What is DCPIP?

A

DCPIP is a dye that goes from BLUE to colourless in the presence of Vitamin C

32
Q

What is the aim of the experiment?

A

To find the concentration of vit c in an unknown solution

33
Q

What is the method of the DCPIP experiment

A
34
Q

What are monosaccharides?

A
  • Monosaccharides are carbohydrates which makes up polysaccharides
  • Glucose is a monosaccharide
    • its Soluble meaning its easy to transport
    • its chemical bonds store lots of energy
35
Q

How do disaccharides from monosaccharides?

A
  • Two monosaccharides can form a glycosidic bond through a condensation reaction to form a disaccharide
  • A disaccharide can be broken through hydrolysis where the glycosidic bond is broken two form 2 monosaccharides
36
Q

What are some examples of disaccharides?

A

Lactose

  • B-glucose + galactose
  • 1,4 glycosidic bond
    ### Sucrose
  • A-glucose + fructose
  • 1,2 glycosidic bond
37
Q

What are some examples of polysaccharides?

A

Amylopectin

  • A-glucose
  • 1,4 and 1,6 glycosidic bonds
  • Lots of side branched
38
Q

What are triglycerides?

A

An insoluble Lipid that contains

  • One molecule of glycerol
  • Three hydrophobic fatty acids tails

Bonded together through ESTER BONDS

39
Q

How are triglycerides formed?

A

Formed through Condensation Reactions

Broken-through Hydrolysis reactions

40
Q

What are unsaturated and saturated lipids?

A

Saturated contains only one type of bond where each carbon is attached to at least 2 hydrogens this results in a higher melting point

Large amounts result in an increased risk of CVD

Unsaturated contains one or more carbon double bonds which results in a kink in the structure (when there is two or more its a polyunsaturated lipid)

41
Q

What are LDL’s and HDL’s

A

LDL = Low Density Lipoproteins

HDL = High Density Lipoproteins

Both are cholesterol and both are needed

42
Q

What are the differences between LDL’s and HDL’s

A
43
Q

What’s the link to CVD

A

High LDL → High Blood Cholesterol → High Blood Pressure → Increased chance of Inflammatory Response → Increased Risk of Atheroma Formation

44
Q

What are some environmental risk factors of CVD

A
  • Diet high in saturated fat
  • High Obesity = Higher chance of CVD
    • Obesity indicators such as Hip Waist Ratio and BMI
    • Allow for people to make appropriate changes
  • Smoking
    • Contains chemicals that decrease lumen size
    • Warnings on packets discourage smoking
  • Low Exercise
    • Excess energy stored as fat build up in arteries
    • When increases cholesterol level if not used
45
Q

What are some genetic risk factors of CVD

A

Genetic Risk Factors of CVD

  • Sex (Male or Female)
    • Males have an increased chance due to a lack of progesterone (found in females menstrual cycle)
    • Progesterone reduces LDL during the menstrual cycle
  • Genetics
    • Some alleles produce code for higher amounts of cholesterol production
    • These alleles are inherited by offspring making them more susceptible to CVD`

[OBSELETE] Edexcel - A Level Bio (9 decks)

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