B2-Organisation Flashcards
What are tissues?
Groups of cells with similar structure and function
What is an organ
A collection of tissues performing specific functions
What is an organ system?
A group of organs with related functions working together to perform certain functions within the body
What are the 3 main nutrients we need as humans in large quantities and why?
Carbohydrates-main source of energy
Protiens-for growth and repair
Lipids-for energy, make up part of cell membranes so essential for normal growth
What are carbohydrates (starch) made up of?
Many glucose molecules
What are lipids made up of?
Fatty acid and glycerol molecules
What are proteins made up of?
Many different amino acids
What is the food test for starch?
Iodine-if it turns blue/black
What is the food test for sugars?
Benedict’s solution-if it turns brick red when heated to 70°C
What is the food test for protein?
Buiret reagent-if it turns purple
What is the food test for lipids?
Ethanol-if it gives a cloudy white layer
What are enzymes referred to as?
Biological Catalysts
What do catalysts do?
They increase the rate of a chemical reaction without being used up themselves
What is the substance the enzyme binds onto called?
The substrate
What is the area between the enzyme and the substrate?
The active site
What is it called when an enzyme and substrate join together?
An enzyme-substrate complex
What is the theory used for enzymes?
The lock and key theory
What are enzymes made of
Proteins
Fill in the blanks:
The substrate has a …………………. shape to the active site so fits together
Complementary
What is metabolism?
The sum of all the reactions in a cell or body
How does temperature affect enzyme activity?
Enzyme activity increases up to the optimum temperature and after that rapidly falls due to the enzyme becoming denatured
What is the result of an enzyme becoming denatured?
If an enzyme has become denatured the shape of the active site changes permantly so it won’t be useful for catalysing any of the same substrates
How does pH affect enzyme activity?
Outside of the optimum pH’s enzyme activity is slowed and some enzymes may become denatured
What are the areas of the digestive system from top to bottom?
- Mouth
- Salivary glands
- Oesophagus
- Stomach
- Liver
- Gall bladder
- Pancreas
- Small intestine
- Large intestine
- Appendix
- Rectum
- Anus
What does bile do?
- Neutralise acid from stomach
- Emulsifies lipids to form droplets
What are the 2 sections of the small intestine?
The duodenum and the illeum
What enzymes are used to digest Carbohydrates and where are they found?
- Carbohydrases
- Salivary glands, Small intestine
What enzymes are used to digest Proteins and where are they found?
- Proteases
- Stomach-pepsin, Duodenum-tripsin, Ileum-peptidase
What enzymes are used to digest Lipids and where are they found?
- Lipases
- Pancreas, Small intestine
What are the components of the blood?
- Plasma
- Red blood cells
- White blood cells
- Platelets
What substances does the blood transport?
- Oxygen
- Carbon dioxide
- Glucose
- Urea
- Antibodies
- Hormones
Describe an artery
- They carry oxegynated blood away from the heart
- They can withstand high pressure
- They have a thick muscular made up of collagen and elastin
- They have a small lumen
Describe a vein
- They carry deoxygenated blood towards the heart
- They only need to withstand low pressure
- They have a thin wall
- They have a large lumen
Describe a capillary
- Blood slows down and leaks oxygen+glucose
- They have walls a single cell thick
- Tiny lumen
What do valves do in blood vessels?
Prevent backflow
What are our blood vessels arranged in?
A double circulatory system
What is the blood circulation for the lungs?
Pulmonary
What is the blood circulation for the body?
Systemic
What causes blood in veins to move?
Random muscle contractions
What is important to remember when looking at pictures of the heart?
It is flipped around meaning that the left side is displayed in the right and vice versa
What are the 4 chambers of the heart starting from looking at the top left and going clockwise round?
- Right atrium
- Left atrium
- Left ventricle
- Right ventricle
What are the 4 coronary arteries in the heart?
- Vena cava
- Pulmonary artery
- Pulmonary vein
- Aorta
What coronary arteries are located in the left half of the heart?
The aorta and the pulmonary vein
What coronary arteries are located in the right half of the heart?
The vena cava and the pulmonary artery
What does the vena cava do?
It brings de-oxygenated blood into the heart
What does the pulmonary artery do?
It takes de-oxygenated blood to the lungs
What does the pulmonary vein do?
It brings oxgenated blood from the lungs back to the heart
What does the aorta do?
It carries oxygenated blood around the body
List the path blood takes through the heart
- Body
- Vena cava
- Right atrium
- Right ventricle
- Pulmonary artery
- Lungs
- Pulonary vein
- Left atrium
- Left ventricle
- Aorta
- Body
Why is the muscular heart wall thicker on the left side?
It has to pump the blood all around the body-not just the lungs
What do ventricles do?
Pump blood out of the heart
What is coronary heart disease?
When fatty deposits build up in the coronary arteries (this forms a plaque)-this narrows the walls of the arteries and causes blood pressure to increase-also blood flow is reduced meaning less glucose and oxygen reach the heart for respiration
What are treatments to coronary heart disease and how do they work?
- Stents-a metal mesh that is placed in the artery-a tiny balloon is inflated to open up the blood vessel and the stent at the sane time-the stent remains in place holding the blood vessel open
- Bypass surgery-part of the coronary artery can be replaced by a vein from another part of the body-this works for badly blocked arteries that stents cannot help
- Statins-these reduce cholesterol levels and slow down the rate in which fatty material is deposited in the coronary arteries
What are the risk factors for coronary heart disease?
- Genetic factors
- Age
- Diet
- Lifestyle choice-e.g smoking
What does LDL stand for and what do these do?
Low density lipoproteins-these transport cholesteral into the body-these are bad for us and are caused by eating saturated fat : (
What does HDL stand for and what do these do?
High density lipoprotiens-these return cholesterol to the liver-these are good for use and are caused by eating polyunsaturated fats : )
What is worse-a blockage of a coronary artery near a junction or further along
Near a junction-blood supply is completely cut off
What are some artificial ways we can help the heart?
- Artificial valves
- Artificial pacemakers
- Artificial hearts
What do heart valves do?
They prevent the backflow of blood
How may a heart valve become faulty?
It may not open as wide as is normal or close properly
What can damaged heart valves be replaced by?
Biological or mechanical valves
When are artificial pacemakers used?
When a person’s heart beats abnormally-this can be abnormally slow, fast or irregular
What is an artificial pacemaker?
A small battery-operated electronic device implanted into a person’s chest
Where is an artificial pacemaker located in the heart?
The right atrium
When are artificial hearts used?
They are used when a patient is waiting for a heart transplant or while waiting for their heart to recover
Describe the path oxygen takes from the mouth/nose into the bloodstream
Oxygen enters the body through the mouth, down the trachea (windpipe), down the bronchi, down the bronchioles, into the alvioli (miniature air sacks). The oxygen then moves into blood vessels surrounding the alveoli via diffusion and binds to hemoglobin.
What 2 substances are transferred between the alveoli and capilleries?
Oxygen and carbon dioxide
How are the alveoli adapted for diffusion?
- Thin walls-short distance for gases to travel
- Spherical shape-large surface area to volume ratio
What is the process of breathing called?
Ventilation
What surrounds the lungs?
Intercoastal muscles and the diaphragm
What causes air to be drawn in and out of the lungs?
Atmospheric air pressure
What are the organs in plants and what do they do?
- Leaves-take in sunlight for photosynthesis
- Stem-transport of water and sugar
- Roots-absorb water, minerals, anchor plant
What is the function of the palisade mesophll?
They are packed with chloroplasts to absorb light efficiently
What is the function of the spongy mesophyll?
Tissue is packed loosely for efficient gas exchange-they are covered in a thin layer of water and gases dissolve in this water as they move into and out of the cells
What is the function of the guard cells?
To control the opening and closing of the stomata
What is the function of the stomata?
To allow gases to move in and out of the leaf
How are the phloem and xylem arranged in the stem?
In bundles
How are the phloem and xylem arranged in the root?
A large xylem surrounded by seperate phloems
What is the function of the phloem?
To carry organic molecules
What is the function of the xylem?
To carry water and dissolved mineral ions
List features of the phloem
2 way, end wall sieve plates, cells are living but they need companion cells
List features of the xylem
1 way-upwards, no ends between cell walls, not living, lignin in the cell walls
What is the loss of water vapour from the surface of leaves called?
Transpiration
Where is water lost in plants?
When the stomata opens to let carbon dioxide in (the underneath of the leaves)
What is the source in translocation in winter?
The leaves
What is the sink in translocation in winter?
The starch underneath the ground (e.g) potatoes
What is the source in translocation in summer?
The starch underneath the ground (e.g) potatoes
What is the sink in translocation in summer?
The leaves
What factors increase transpiration?
- Increased temperature
- Decreased humidity
- Increased wind speed
- Increased light intensity
What is a non-communicable disease?
A disease that can’t be transferred between people or other organisms
What are examples of non-communicable diseases?
Cancer, Diabetes, Genetic diseases, Heart disease, Neurological disorders
What are risk factors for non-communicable diseases?
- Diet
- Lifestyle
- Stress
When does a tumour form?
When a cancerous cell divides rapidly
What are the 2 types of tumours?
Benign and malignant tumours
What are benign tumours?
Tumours that grow slowly-usually within a membrane, can easily be removed and doesn’t invade other parts of the body
What are malignant tumours?
Tumours that grow quickly, invade neigbouring tissues and can be spread to other parts of the body in the bloodstream-secondary tumours can form
What is it called when secondary tumours form?
Metistasis
What are carcinogens?
Chemicals and other agents that cause cancer
What are risk factors for cancer?
- Cigarettes
- Alcohol intake
- Exposure to ultraviolet radiation
- Exposure to ionising radiation
- Exposure to chemical carcinogens
- Genetic risk factors
What are 3 ways of treating cancer?
- Surgery
- Radiotherapy
- Chemotherapy
