Structure and Functions in Living Organisms Flashcards
1
Q
Level of organisation
Cells, Tissues, Organs, Organ System
A
- A cell is a group of organelles working together to perform the same function
- A tissue is a group of cells working together to perform the same function
- An organ is a group of tissues working together to perform the same function
- An organ system is a group of organs working together to perform the same function
2
Q
What elements are found in carbohydrates (glucose)+ how to test for it
A
- Carbon, Hydrogen and Oxygen
- Heat solution in water and add Benedict’s solution, turns from blue to:
- green or yellow in low concentration
- brick red in high concentration
3
Q
What elements are found in protein + how to test for it
A
- Carbon, Hydrogen, Oxygen and Nitrogen
- Add biuret solution, turns from blue to purple
4
Q
What elements are found in lipids + how to test for it
A
- Carbon, Hydrogen and Oxygen
- Add ethanol + water to the solution and shake, if positive test a milky white emulsion forms
5
Q
What is starch made up of and how to test for it
A
- Made up of simple sugars (glucose) joint together
- Add iodine solution, if positive test the sample should turn blue-black
6
Q
What are enzymes
A
- Biological catalysts
- Which speed up the rate of reaction without being used up
7
Q
What is metabolism
A
It’s the rate at which chemical reactions take place in the body
8
Q
What’s an active site
A
An area of an enzyme where substrate attaches
9
Q
What is diffusion
A
- net movement of particles
- from area of high concentration to an area of low concentration
10
Q
The effect of too high temperature on enzyme activity + the effects of too high or too low pH on enzyme activity
A
- Decreases activity
- Enzyme denatures and substrate can no longer fit the active site
11
Q
What are the factors affecting diffusion
A
- Temperature
- Concentration gradient
- Surface area to volume ratio
- Distance
12
Q
What is osmosis
A
- net movement of water molecules
- across a partially permeable membrane
- from area of high water conc. to area of lower water conc.
13
Q
What is active transport
A
- net movement of particles
- from area of low concentration to an area of high concentration
- requiring energy
14
Q
What’s a limiting factor
A
- Factor in a reaction which is in the shortest supply
- Lack of this factor is the reason why the rate of reaction no longer increases
15
Q
What is the process of photosynthesis
A
- Photosynthesis is the process where plants make their own ‘food’ (the food it produces is glucose)
- Chloroplast contains chlorophyll which absorbs sunlight and uses the energy to convert CO2 and H2O into glucose and water
16
Q
Why is rate of photosynthesis low in the morning
A
- Carbon dioxide levels are high
- Temperature is a limiting factor
- Low temperature inhibits enzyme activity
17
Q
Why is rate of photosynthesis high at midday
A
- High temp maximises enzyme activity
- Carbon dioxide is a limiting factor as it is in the shortest supply
18
Q
Whats magnesium needed for in plants
A
- Needed to produce chlorophyll in plants
- Not enough leads to leaves yellowing
19
Q
Whats nitrogen needed for in plants
A
- Nitrates = source of nitrogen which is needed to make amino acids for protein
- Not enough causes stunted growth and yellowing of leaves
20
Q
What’s contained in the top half of a leaf + their functions
A
- Waxy Cuticle: Prevent evapouration of water
- Upper epidermis: Transparent to allow light to enter leaf
- Palisade Mesophyll: Contains lots of chloroplast for photosynthesis
21
Q
What’s contained in the bottom half of a leaf + their functions
A
- Spongy mesophyll air spaces: Allows gases to diffuse
- Xylem: Allows entry of water into leaf by tranpiration stream
- Phloem: Takes away glucose produced from photosynthesis
- Guard cells: Controls opening and closing of stomata
- Stomata: Allows CO2 to enter the leaf
22
Q
How is a leafs structure better adapted for photosynthesis
A
- Thin; so gases don’t have to diffuse far
- Large surface area; so it can absorb more light
23
Q
Carbohydrates
source + function
A
- Pasta, rice
- Provides energy
24
Q
Proteins
source + function
A
- Meat
- Important for growth and repair of muscles
25
Lipids / Fats
source + function
* Butter
* Provides energy + provides insulation
26
Vitamins A, C and D
source + function
A:
* Liver
* Helps improve vision
C:
* Oranges
* Helps to prevent scurvy
D:
* Eggs
* Needed for strong bones
| LOE
27
# Mineral Ions
Calcium + Iron
source + function
Calcium:
* Milk
* Needed to make strong teeth + bones
Iron:
* Red meats
* Needed to make haemoglobin for healthy blood
28
Fibre
source + function
* Fruits + Vegetables
* Aids movement of food through gut
29
Water
function
* Constant supply to replaces water loss from sweating, urinating, breathing
30
Bile function
* PRODUCED in liver, STORED in gall bladder and RELEASED into the small intestine
* Bile is alkali, it NEUTRALISES the hydrochloric acid from the stomach
* BIle EMULSIFIES fat - it breaks down large lipid molecules into smaller ones to increase surface area
31
What is peristalsis
* Muscular contractions that squeeze boluses of food through your gut
32
# The Alimentary Canal
What happens in the mouth?
* Teeth break down food into smaller parts
* Enzyme amylase in the saliva start to break down starch
33
# The Alimentary Canal
What happens in the stomach?
* Stomach contracts to break down food into smaller pieces
* Proteases start to break down proteins in the stomach
* Produces hydrochloric acid to kill bacteria
34
# The Alimentary Canal
What happens in the pancreas?
* Pancreas secretes digestive enzymes into small intestine;
* Proteases (protein), Amylase (carbs) and Lipase (lipids)
35
# The Alimentary Canal
What happens in the small intestine?
* Absorbs nutrients into the body
* First part is the deodenum and last part is called the ileum
* The walls of the SI are covered in villi which have a large surface area for more absorption
36
# The Alimentary Canal
What happens in the large intestine?
* This is where excess water is absorbed
* After water's absorbed, the undigested food leaves the body as faeces
37
How is the structure of villi important
* Villi is covered in **microvilli** which** increases the SA for absorption** even more
* Each villus contains capillaries to maintain quick absorption of **nutrients**
* In the middle of the villus is a lacteal which is responsible for absorbing fat
38
What is respiration?
* It's the process of transferring energy from glucose
* This transferred energy is made into ATP which provides energy to cells
39
Aerobic respiration word + chemical equation
Oxygen+Glucose->Carbon Dioxide+Water+ATP
6O2 + C6H12O6 ---> 6CO2 + 6H20 + ATP
40
Anaerobic respiration word equation in humans + plants
Glucose -----> Lactic acid + energy
Glucose -----> Ethanol + Carbon Dioxide + energy
41
What do the goblet cells and cilia do?
* Goblet cells secrete mucus which traps bacteris
* Cilia, located in the trachea and lungs, have hair like projections that waft the mucus up to your mouth
42
What happens when you breathe in?
* Intercostal muscles + diaphragm contract/flattens out
* Thorax increases in volume + ribs move up and out
* This decreases the pressure drawing air in
43
What happens when you breathe out?
* Intercostal muscles + diaphragm relax
* Thorax decreases in volume + ribs move down and in
* This increases the pressure, forcing air out
44
How are alveoli adapted for gas exchange?
* They have large surface area
* Thin walls to short diffusion pathway
* Moist to dissolve gases
* Great blood supply
45
How does smoking effect the body?
* Contains carcinogens leads to lung cancer
* Smoking damages the walls of alveoli ---> decreasing surface area for gas exchange ---> disease called emphysema
* Tar causes cilia to paralyse ---> build up of mucus and pathogens ---> bronchitis and smokers cough
* Carbon monoxide binds irreversably to haemoglobin ---> reducing amount of oxygen ---> heart rate increases to make up, high blood pressure ---> increased risk of coronary heart disease and heart attacks
46
Components of blood
* Red blood cells
* White blood cells
* Plasma
* Platelets
47
What do platelets do + how do they do it?
* Clot the blood at the site of a wound
* In a clot, platelets are held together by a mesh of protein called fibrin
48
What substances are transported in plasma?
* (soluble products) Glucose, Amino Acids
* Hormones, Carbon Dioxide, Urea
| GACHU
48
How are red blood cells adapted for their function?
* Have a bioconcave disc shape, increases surface area to absorb and release oxygen
* Don't have a nucleus, frees up space for more haemoglobin so they can carry more oxygen
* They contain haemoglobin (which contains lots of iron), haemoglobin reacts with oxygen to form oxyhaemoglobin
49
What are the 2 types of white blood cells + explain what their role is
* Phagocytes
* Lymphocytes
50
How do phagocyte
Detect things that are foreign in the body and then engulf the pathogen and digest them
51
How do lymphocytes work + explain memory cells
* Recognise antigens (every pathogen has a unique molecule called antigen)
* Produce antibodies (proteins) which destroys pathogens by:
- Labeling the pathogen so it's easily recognisable by phagocytes
52
How do vaccinations work
* Vaccinations involve injecting dead pathogens into the body which carry antigens
* They trigger an immune response; your lymphocytes produce antibodies
* Memory cells will be produced, if those same pathogens infect you, antibodies to kill them will be produced **much quicker** and in a **larger quantity**
53
Pulmonary is for...
Hepatic is for...
Renal is for...
Veins
Artieries
* Lungs
* Liver
* Renal
* Bring blood to the heart
* Take blood away from the heart
54
How is oxygenated blood sent to the body
* Oxygenated blood is brought from the lungs to the pulmonary vein
* To the left atrium, contracts and forces blood into left ventricle
* Left ventricle contracts, pumping the blood around the body via the aorta
55
How is deoxygenated blood brought from the body
* Deoxygenated blood is brought from the body to the heart by the vena cava
* Takes blood into the right atrium, contracts and forces blood into the right ventricle
* Right ventricle contracts and pumps blood to the lungs via the pulmonary artery
55
How does the heart rate change during exercise?
* When you exercise, you produce more CO2 bc muscles are respiring more
* High levels of CO2 in blood is detected by the receptors in the aorta and carotid artery (artery in the neck)
* This sends impulses to the brain, brain sends signla to heart causing it to contract more frequently
56
How does the heart rate change under the influence of adrenaline?
*
57
What are some factors that can lead to coronary heart disease
* Having a diet high in saturated fat
* Smoking
* Being inactive
* High blood pressure
57
How are the arteries adapted for its function
* It has a narrow lumen, blood will be forced through at high pressures
* Thich muscle walls; walls of the artery should be thick to withstand high pressure
* Elastic fibre walls; to allow arteries to expand
58
How are veins adapted for its function
* It has a wider lumen, blood flows at much lower pressure
* Therefore the walls don't need to be as thick
* They have valves which prevents the backflow of blood
59
How are capillaries adapted for its function
* Capillaries are one cell thick to enable a very short diffusion distance
60
What is excretion
Removal of waste products of metabolism
61
What are the excretory products of the body
* Urea in the kidneys
* Carbon Dioxide from the lungs
* Sweat from the skin
62
What are auxins
Auxins are plant hormones
63
Why do plant grow towards the light
* When a shoot is exposed to light, the auxin accumulates on the side that's more shaded
* Makes the cells elongate and shoot bends towards light
63
What's the difference between hormonal and nervous communication
* Hormonal: Chemicals that travel in your blood
- Slower messages
- Responses are long lived
- They act in a more general area
* Nervous: Invloves the use of electrical impulses
- Much faster message
- The electrical impulses will act on a specific area
- Responses are short lived
64
How does the CNS coordinate information
* The stimulus (a book) is detected by the receptors
* They send electrical impulses along the sensory neuron to the CNS
* Electrical impulses then pass along to the motor neuron to the effector
64
What does the CNS consist of
Brain and Spinal Cord
65
What is a synapse
* The connection between 2 neurons, this is where a neurotransmitter is released
* The nerve signals are transferred by chemicals called neurotransmitter which diffuses across the gap
66
How does a reflec arc work
* The receptor detects the stimulus (fire)
* Electrical impulses are then sent along the sensory neurons to the CNS
* In the CNS the sensory neurons pass the electrical impulses to the relat neuron
* The relay neuron relays the impulses to the motor neuron, which travel along the moto neuron the effector
* Muscle then contracts and moves hand away from fire
67
What happens to the eye when focusing on distant objects
* Ciliary muscles relax
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