Organisation Flashcards
1
Q
Define enzyme
A
a biological catalyst that controls the rate of reactions in our body
2
Q
Define catalyst
A
a substance which increases the speed of a reaction without being used up
3
Q
Why can enzymes only catalyse one specific reaction?
A
because their active site has a unique shape that matches with a substrate - ‘lock and key’
4
Q
What two factors can cause an enzyme to denature?
A
- temperatures that are too high
- a pH that is either too high or low
5
Q
What happens when an enzyme denatures?
A
the shape of the active site changes
6
Q
- Name 3 digestive enzymes
- What molecules they break down
- what the molecules convert into
A
- Protease : Proteins -> Amino acids
- Lipase : Lipids -> glycerol + fatty acids
- Amylase : starch -> maltose
- (Carbohydrase : Carbohydrates -> simple sugars)
7
Q
Why is it important that food molecules are broken down during digestion?
A
So they are soluble and can be absorbed into the blood stream
8
Q
Where is amylase made?
A
- Pancreas
- Small intestine
- Salivary glands
9
Q
Where are proteases made?
A
- Pancreas
- Small intestine
- Stomach (where it’s called pepsin)
10
Q
Where are lipases made?
A
- Pancreas
- Small intestine
11
Q
Where is bile produced, stored and released?
A
- Produced - liver
- Stored - gall bladder
- Released - small intestine
12
Q
Why does bile neutralise acids?
A
Because it’s an alkaline. The enzymes work best in these alkaline conditions.
13
Q
Why does bile emulsify fats?
A
Because the fats break into tiny droplets they have a bigger surface area for enzymes to work on - making digestion faster.
14
Q
Why does the stomach produce hydrochloric acid?
A
to kill bacteria,
to give the right pH for protease to work
15
Q
How do you prepare a food sample?
A
- Break it up using a pestle and mortar
- Transfer to beaker, add some distilled water
- Stir with glass rod to dissolve some of the food
- Filter the solution using a funnel lined with filter paper to remove solid bits of food
- …
16
Q
Which solution do you use for each food test?
A
Sugars - benedict’s solution
Starch - iodine solution
Proteins - biuret solution
Lipids - ethanol
17
Q
What colour’s shown when sugar is present?
A
from blue to green, yellow, brick-red
in ascending order of how much is present ->
18
Q
What colour’s shown when starch is present?
A
from browny-orange to blue-black
19
Q
What colour’s shown when protein is present?
A
from blue to purple
20
Q
What colour’s shown when lipids are present?
A
cloudy-white
21
Q
What food test requires a water bath at 75C ?
A
test for sugars
using benedict’s solution
22
Q
What food test should not be filtered when preparing a food sample?
A
test for lipids
because it sticks to the filter paper
23
Q
What should you do after adding a solution to your food samples?
A
gently shake the test tube
24
Q
How does air travel through when breathing in?
A
trachea -> bronchi -> bronchioles -> alveoli
25
What is **breathing rate**?
**Number** of **breaths** per **minute**
26
Where and what does the **right ventricle** pump?
* It pumps **deoxygenated** blood
* **to** the **lungs** and then into the **heart**
27
Where and what does the **left ventricle** pump?
* It pumps **oxygenated** blood
* to the **other organs**
* as it **becomes deoxygenated** the blood returns to the right ventricle
28
Name the **four chambers** of the **heart**
* left **ventricle**
* right **ventricle**
* left **atrium**
* right **atrium**
29
Where is each **blood vessel** of the heart **located**?
* vena cava - top **left**
* pulmonary artery - top centre **left**
* aorta - top centre **right**
* pulmonary vein - top **right**
| this is when looking at a diagram - in your heart it's the other way rou
30
What is the **function** of the **coronary arteries**?
to provide **oxygen** for the **muscle cells** of the heart
31
What does the **pacemaker** do?
Where is it **located**?
**controls** your resting **heart rate** by sending an **electrical impulse** causing surrounding **muscle cells** to **contract**
in the **right atrium**
32
What can you use if your **pacemaker** cells **don't work** properly?
Use an **artificial pacemaker**
which connects to the heart with a **wire** and sends **electrical** **impulses**
33
How are **veins** **adapted** to carry **blood** back **to the heart**?
* **thin walls** since it already has a **low pressure**
* **valves** to stop **back flow**
34
How are **arteries** **adapted** to carry blood **from the heart**?
* **thick muscular walls** to withstand the **high pressure**
* **elastic fibres** to **stretch** and **recoil** for every surge of blood
35
How are **capillaries** adapted for **diffusing substances**?
* **thin walls** (only one cell thick)
* **permeable walls** - so substances can **diffuse** **in** and **out**
* carry blood close to every cell in the body
36
How are **red blood cells** adapted for **absorbing oxygen**?
* they are a **biconcave disc** giving it a **large surface area**
* **no nucleus** which allows **more space** for oxygen
* contain **haemoglobin** which **binds to oxygen**
37
What is the **word equation** that involves **haemoglobin** and **oxygen**?
haemoglobin + oxygen --> oxyhaemoglobin
| this happens in the lungs
it is the opposite when depositing oxygen
38
What **three** ways can **white blood cells** **fight** against a **microorganism**?
* **phagocytosis**
* producing **antibodies**
* producing **antitoxins**
39
What do **white blood cells** have that **red** **blood cells** don't?
a **nucleus**
40
What do **platelets** do?
they help the **blood** to **clot**
| this stops excessive bleeding
41
What does **plasma** do?
Transports:
* **red** + **white** blood cells and **platelets**
* **CO2** from **organs** to **lungs**
* **Urea** from **liver** to **kidney**
* **Nutrients** e.g. **glucose** and **amino acids**
42
What is **coronary heart disease**?
When the **coronary arteries** get blocked by layers of **fatty material building up** which **restricts blood flow** causing **lack of oxygen** in heart muscles
| this can lead to heart attacks
43
What are **two** ways you can **treat** coronary heart disease?
* using **stents**
* taking **statins**
44
What are the **positives** of **stents**?
* they **lower** the risk of **heart attack**
* **effective** for a **long time**
* **recovery time** is relatively **quick**
45
What are the **negatives** of **stents**?
* risk of **heart attack** *during* operation
* risk of **infection** from surgery
* risk of developing **thrombosis** (developing a *blood clot* near the *stent*)
46
What do **statins** do?
**reduce** the amount of 'bad'/LDL **cholesteral** in the **bloodstream**
| this slows down the rate of fatty deposits forming
47
What are the **positives** of using **statins**?
* can **increase** 'good' / **HDL cholesteral** which can **remove** **LDL cholesteral**
* they have been **proven** to **reduce the risk** of coronary heart disease
48
What are the **negatives** of using **statins**?
* can sometimes have **negative side effects** e.g. *headache*, *kidney failure,* *liver damage*
* it's a **long-term drug** that must be taken **regularly**. Risk that someone **forgets**
49
What can a **heart valve** be **weakened** by?
* heart attacks
* old age
* infection
50
How can **weak heart valves** lead to **poor blood circulation**?
Valve tissue may **stiffen** and **not open** properly
A valve can become **leaky** and allow **blood flow** in **both directions**
| this means blood doesn't circulate as effectively as normal
51
How can **faulty heart valves** be **treated**?
**Replacing** the valve with:
* **biological** (human or mammal) **valves**
* **mechanical** (man-made) **valves**
52
What are the **negatives** for a **mechanical valve**?
* issues with **blood clots**
* patients need to take **anti-clotting drugs**
53
What are the **negatives** for a **biological valve**?
* they don't last long
| but patients don't need to take drugs
54
What are the **positives** of **artificial hearts**?
* they **aren't rejected** by the **patients body** because they're made of *plastic* and *metal*
* they can be **used** when a **donor isn't available**
55
What are the **negatives** of **artificial hearts**?
* surgery can lead to **bleeding** and **infection**
* they **don**'t work **as well** as **natural** ones
* **motor** could **fail** or parts of the heart could **wear out**
* blood **doesn't flow** through artificial hearts as **smoothly** which can cause **blood clots** or **strokes**
therefore, patients have to take **anti blood clotting drugs** which can cause **problems with bleeding** if they're hurt
56
What is the point of **artificial blood**?
to act as a **blood substitute** to replace the **lost volume** of blood which can give the patient enough time to **produce new blood cells**
| it can keep a person alive even if they lose 2/3 of their red blood cell
57
What are the **2 types** of **tumours**?
* Benign
* Malignant
58
What is a **benign tumour**?
A tumour which **doesn't invade** other **tissues** of the body.
It stays in **one place** (usually inside a **membrane**).
| It **isn't** cancerous
59
What is a **malignant** tumour?
A tumour that **spreads** to neighbouring **healthy tissues**.
**Cells** can **spread** via the **bloodstream** and cause **secondary tumours**.
| They are **cancers** and can be fatal
60
What are **4** **risk factors** that increase the **risk of cancer**?
* **Smoking**
* **Obesity**
* **UV exposure**
* **Viral infection** e.g. hepatitis B/C increase risk of liver cancer
61
What are **tumours** the **result of**?
**uncontrolled** cell **growth** and **division**
62
Where is the **epidermal tissue** of a leaf **found**?
on the **top** (*upper* **epidermis**)
on the **bottom** (*lower* **epidermis**)
63
What are the **features** of the **upper epidermis**?
It's covered by a **waxy cuticle** to **reduce evaporation** of **water**
It's **transparent** so that **light** can pass through
64
What layer is **under** the **upper epidermis**?
**palisade mesophyll**
| where photosynthesis happens
65
Why is the **palisade mesophyll** good for **photosynthesis**?
It contains **palisade cells** which have lots of **chloroplasts**
| chloroplasts have chlorophyll which absorb light for photosynthesis
66
What layer is **under** the **palisade mesophyll**?
**spongy mesophyll**
| for gases to diffuse
67
Why are there **air gaps** in the **spongy mesophyll**?
to allow **CO2** to diffuse **into** the **palisade cells**
to allow **oxygen** to diffuse **out** of **palisade cells** and go **through the stomata**
68
Where are **stomata** and **guard cells** found?
in the **lower epidermis**
69
Define **translocation**
the **movement of sugars**, from **photosynthesis**, through the **phloem** to the **rest** of the **plant**
70
Define **transpiration**
the evaporation of water from a leaf's surface
71
What conditions **increase** the **rate of transpiration**?
* **high temperature**
* **dry** conditions (not humid)
* **windy** conditions
* **high light intensity**
72
Do *guard cells* **open** or **close** during the **night**?
They **close** because **photosynthesis** *can't* occur with **no light**
| they open to let CO2 enter
73
Describe the **structure** of **xylem**
* Made up of **dead cells** joined **end to end**
* There are **no walls** between them creating a tube
* It is strengthened by **lignin**
