Organisation (1) Flashcards
Red blood cell structure and function-
Plasma-
Platelets-
White blood cells-
Red blood cell- bi-concave disk structures with high surface area
contains red pigment haemoglobin which binds to oxygen to form oxyhaemoglobin
no nucleus
Plasma- Yellow liquid that carries the other three structures
also carries nutrients like glucose, amino acids, hormones, CO2, urea, thermal energy etc
Platelets-small fragments of cells that cause blood clotting
when a blood vessel is damaged, platelets bind to the wound to prevent further blood loss
the release of clotting factors (proteins) causes a series of reactions which form fibrin fibres that trap red and white blood cells to create a solid clot
White blood cells- Lymphocytes- produce antibodies to neutralise pathogens then remember how to create them for the future
Phagocytes- engulf and destroy pathogens via phagocytosis
Order of blood flow through the heart and lungs
Deoxygenated blood enters in the vena cava
right atrium
right ventricle
pulmonary artery
blood becomes oxygenated in the lungs
pulmonary vein
left atrium
left ventricle
aorta
oxygenated blood flows around the body
Where are pacemaker cells?
What do valves do?
What is the heart made of?
What supplies the heart with blood?
-found in the right atrium
they produce small electrical impulses which cause the muscle cells to contract
can be replaced by a mechanical pacemaker
- prevent blood backflow
-muscle tissue
-coronary arteries
Veins-
Arteries-
Capillaries-
Veins- take the blood back to the heart, formed by capillaries joining
blood flows at a lower pressure so it has a wider lumen and
thin, elastic walls
have valves
Arteries- Carries blood to the body at high-pressure
thick walls, smaller lumen, strong and elastic
Capillaries- one cell thick
branch off of arteries
permeable walls for substance exchange
Solutions to cardiovascular disease:
Statins-
Stents-
Artificial hearts-
Biological/mechanical valves-
Artificial blood-
Statins- drugs which reduce blood cholesterol an thin blood so it can more easily pass through capillaries
(cons- must be taken regularly, can have negative side
effects, takes a while for effects to take place)
Stents- Mesh tubes which are inserted into arteries to keep them
open so blood can pass through (cons- the risk of infection in
surgery)
Artificial hearts- mechanical devices that pump blood instead of a
faulty heart in the case of a heart attack to keep a
patient alive until a donor can be found
(cons- big surgery needed, huge risk of infections
and high chance of the device failing)
Biological/mechanical valves- faulty valves can be replaced
can obtain replacements from other
mammals (cows and pigs) or
mechanical devices (cons- major
surgery and risk of blood clots)
Artificial blood- a salt solution which replaces the lost blood
It buys time until the patient can receive blood transfusion
What are enzymes?
Explain the lock and key principle
What temperature and Ph level do enzymes work best at?
-Biological protein catalysts that break down molecules
-Every enzyme has an active site which fits onto the specific substrate of the substance being broken down
The enzyme remains unchanged after it works
-enzymes work faster with increased heat up until 40*c when they denature (active site breaks down)
- The optimum Ph level for most enzymes is 7, however some work best in acidic conditions (eg, pepsin breaks down proteins in the stomach and worst best at Ph 2)
Amylase-
Maltase-
Protease-
Lipase-
(Where are they made)
Amylase- convert starch into maltose
made in the pancreas, salivary glands and small intestine
Maltase- breaks maltose into glucose. Made in small intestine
Protease- converts proteins into amino acids
made in the pancreas and small intestine
Lipase- converts fats into glycerol and fatty acids made in the pancreas and small intestine
(function and enzymes released)
Salivary glands-
Stomach-
Pancreas-
Liver-
Gall Bladder-
Large Intestine-
Small Intestine-
Rectum-
Salivary glands- produce amylase in saliva
Stomach- Pummels food with a muscular wall
Produces pepsin (an enzyme that breaks down proteins)
Produces Hydrochloric acid to kill bacteria and create optimum Ph conditions for pepsin
Pancreas- Produces protease, amylase and lipase then releases them into the small intestine
Liver- produces alkaline bile, which neutralises the stomach acid so enzymes can work optimally and emulsifies fats (increases their surface area so they can be broken down quicker)
Gall Bladder- stores bile
Large Intestine- absorbs excess water from food
Small Intestine- Produces protease, amylase, maltase and lipase
Absorbs digested food into the blood by structures called villi that increase the surface area of the digestive system
Rectum- where faeces are stored before leaving through the anus
Food tests:
Sugars-
Lipids-
Starch-
Proteins-
Sugars- add benedicts to a food sample and leave in a warm water
bath (60-80*c) for 5 minutes
It goes from blue to green, yellow or brick-red depending on
the sugar concentration
Lipids- add sudan III to the food sample and shake
A red ring forms at the top of the clear solution in the presence of
lipids
Starch- Iodine goes from orange to blue/black in the presence of
starch
Proteins- add biurets to the food sample and shake. The colour changes from blue to pink in the presence of protein
Investigating effects of Ph level on Enzymatic reactions RP (spotting tile)
- Add a drop of iodine to every well in a spotting tile
- Heat water to 35*c using a water bath
- Add 1cm3 of amylase and 1cm3 of a Ph 5 buffer solution into the boiling tube and place in the water for 5 mins
- add 5cm3 of starch to the boiling tube, mix the contents and start a stopwatch
- add a drop of the solution to a well in the spotting tile using a pipette every 30 seconds
- When the iodine remains orange, starch is no longer present
- Determine the time taken for starch to break down by multiplying the number of wells by 30 seconds
- Calculate the rate of reaction by doing 1000/time
- repeat with different Ph buffer solutions to see how Ph affects the time
Describe the process of inhalation and exhalation
Inhalation-
-diaphragm contracts allowing the chest to expand and draw in air as the pressure is lower
Intercostal muscles cause ribs to move out to allow lungs to inflate
Exhalation-
-The diaphragm relaxes as the lungs deflate and push CO2 back out through the respiratory system due to the increased pressure
-The ribs move back inwards
Describe the path of air flow in the respiratory system
-Air enters through the nostrils, then goes down the oesophagus, trachea, bronchi and bronchioles and finally to the alveoli
How does gas exchange occur in the lungs?
-The lungs contain millions of alveoli (air sacs) surrounded by capillaries
-Oxygen diffuses out of the alveoli (high concentration) into the blood (lower concentration)
-CO2 diffuses from the blood (higher concentration) into the alveoli (lower concentration) and is then exhaled through the lungs
-Where are the lungs located
-Structures surrounding the lungs (3)
-Located in the thorax (top part of the body) which is separated by the diaphragm
-Surrounded by pleural membranes which act as a lubricant to reduce friction between the lungs and rib cage
-Surrounded by intercostal muscles which pull the ribcage in and out during inhalation/ exhalation
-The ribcage protects vital organs
Risk factors for cancer-
What is a carcinogen?
-Smoking, obesity, UV exposure, Drinking, genetics
Exposure to radiation- cells ionise and form cancer tumours
Viral infections- hepatitis B and C (spread by unprotected sex or sharing needles) increase the risk of liver cancer
carcinogen= something that causes cancer
cancerous and non-cancerous tumours:
Benign tumour- a tumour that grows until there’s no more room and stays in one place
normally not dangerous and isn’t cancerous
Malignant- a tumour that grows and spreads to neighbouring cells, forming new tumours
They are dangerous and cancerous
Leaf Structure
Epidermal tissue- covers the entire plant, is transparent and allows water to run off to the soil for osmosis
Palisade mesophyll tissue- contains chloroplasts that have the green pigment chlorophyll for photosynthesis
spongy mesophyll tissue- contains air space for gas exchange
Stomata- small holes on the underside of the leaf that allow gas to enter
Guard cells- control the opening and closing of the stomata by being more turgid (cells open) or flaccid (closed)
What is translocation
movement of substances like glucose and ions around the plant for use or storage in both directions through phloem tubes
Phloem tubes- made of collums of elongated cells with small pores to allow cell sap to flow
What is transpiration
what factors affect the rate (4)
Constant stream of water being evaporated and diffused from the plants surface and replaced by water from the roots in the xylem tubes
xylem tubes- made of dead cells with no walls between them and a hole down the middle (strengthened by lignin) to carry water and mineral ions from the roots to the stem and leaves in one direction
Factors affecting the rate of transportation:
Light intensity- brighter conditions increase the rate of transpiration to photosynthesize more
Temperature- increased rate of transpiration as water evaporates quicker
Airflow- if the wind blows water vapour away from the leaf, transpiration will occur quicker
Humidity- drier air leads to an increased rate of transpiration
