B2 - Organisation Flashcards
definition of cells
the basic building blocks that make up all living organisms
definition of tissue
a group of similar cells that work together to carry out a particular function
definition of organ
a group of different tissues that work together to perform a certain function
definition of organ system
a group of organs working together to perform a particular function
definition of organism
organ systems that work together to make an entire living being
basic definition of enzymes
biological catalysts
name the organs and their function within the digestive system (not in order)
MOUTH- mechanically breaks down food and mixes it with saliva
SALIVARY GLAND- produces saliva and enzyme amylase
OESOPHAGUS- transports food through to stomach
STOMACH- churns the food and mixes it with hydrochloric acid an produces protease enzyme (pepsin)
SMALL INTESTINE- continues to digest food and absorbs the small soluble molecules
LARGE INTESTINE- where water is absorbed
RECTUM - faeces is stored
ANUS - excretion of faeces
PANCREAS - produces all 3 digestive enzymes (protease, amylase and lipase)
LIVER- produces bile (speeds up enzyme action)
GALL BLADER- stores bile until it gets released into small intestine
what are 3 adaptations the small intestine has
- very large surface area and it has villi which has microvilli - so there will be more efficient absorption of fatty acids & glycerol into the bloodstream
- capillary - good blood supply as there’s loads of capillaries in the villi - efficient and fast resulting in a well-functioning metabolism
- short diffusion distance -food molecules don’t need to travel far which means faster rate of diffusion - this is to keep a good concentration gradient
What is meant by concentration gradient
The gradient distance in concentration of a dissolved substance between a region of high density and low density
What do enzyme do
Enzymes are biological catalysts that speed up the rat of reactions in living organisms. they are a special type of protein.
explain what the folding of amino acids mean for enzymes
enzymes are a protein and proteins are made from chain of amino acids. the folding of the amino acid chain is what gives the enzyme’s active site it’s shape.
What is the lock & key theory
different enzymes have different active site shapes and only a specific subtrate can fit in a specific enzyme’s active site and not a different enzyme’s.
enzyme + subtrate = catalyses the reaction
(enzyme bonded subtrate) is broken down into smaller molecules like glucose
What is meant by metabolism
the sum of all the reactions happening inside an organism
Which 2 factors affect enzymes
- pH
- temperature
what is the optimum pH for protease enzymes
3
what is the optimum temperature for enzymes in the body
37.5 degrees
What does denatured mean
when the shape of an enzyme’s active site has been changed
(between the shape of the amino acids are weak forces that hold the shape of it together but can be broken by too high or low temperatures of pH
2 things that bile does
- enzymes produced in pancreas & mall intestine work best in ALKALINE conditions but when food comes from the stomach into the small intestine it can take some of the stomach’s hydrochloric ACID goes with it. BILE IS AN ALKALINE LIQUID which means it NEUTRALISES any hydrochloric acid that comes from stomach. this maintains the right alkaline conditions needed for the enzymes in the small intestine to work properly
- bile EMULSIFIES fats to form smaller droplets - increasing surface area for enzymes to act on which then increases the rate of reaction (this doesn’t make bile an enzyme)
What does Amylase break down and what are its products
- breaks down starch & carbohydrates
- its product is maltose and glucose
what does Protease break down and what are its products
- breaks down proteins
- its product is amino acids
what does Lipase break down and what are its products
- breaks down lipids (fats & oils)
- its products are fatty acids & glycerol
Where is Amylase produced and where is its site of action
produced in:
-pancreas
-salivary gland
its site of action:
-small intestine
-the mouth
Where is Protease produced and where is its site of action
produced in:
-pancreas
-stomach
-small intestine
its site of action:
-small intestine
-stomach
Where is Lipase produced and where is its site of action
produced in:
-pancreas
-small intestine
its site of action:
-small intestine
Where is 1 place that are all 3 digestive enzymes produced and where is 1 place where they all have a site of action
- all produced in PANCREAS
- all in SMALL INTESTINE
When lipids are digested the pH of the blood gets lower. Suggest why this happens?
Lipids are digested into fatty ACIDS and glycerol. Fatty acids are ACIDIC so when they are absorbed, the pH of the blood will lower as acids are lower down on the pH scale.
Name 4 components of the blood
Plasma - 55%
Red Blood Cells - 45%
White Blood Cells - <1%
Platelets <1%
Name the 3 blood vessels and what they do
Arteries:
- carries blood Away from the heart to the organs
- high pressure, thick muscular walls with elastic fibres, small lumen
Capillaries:
- brings blood to the cells of the body
- substances diffuse in and out of the blood
- very thin walls = easy for diffusion
Veins:
- carry blood from the organs back to the heart
- low pressure, wide lumen=helps blood flow, valves prevent backflow
order of breathing in from the lungs
nose/mouth
trachea
bronchi
bronchioles
alveoli
How are alveoli adapted to their function
- it is ventilated - air is brought in and out of the lungs
- good blood supply as it is surrounded by capillaries - maintains steep concentration gradient
- the walls of the alveoli are very thin = short diffusion pathway
- they have a large surface area to volume ratio, maximising diffusion
Adaptation of gills in fish
- filaments in gills provide large S.A.
- filaments have good supply (capillaries)
- 1 cell thick = short diffusion path
- they are ventilated
- counter current (blood moves in the opposite direction to the flow of water = maintains a steep concentration gradient)
What is the order of how blood flows in through the heart and around the body
- blood flows into the 2 atria from the vena cava and pulmonary vein
- the atria contract, pushing the blood into the ventricles
- the ventricles contract forcing the blood into the pulmonary artery and the aorta and out of the heart
- blood then flows aroud to the organs through arteries and returns through the veins
- the atria fill again and the whole cycle starts over
(heart also needs its own oxygenated blood, arteries called coronary arteries branch off the aorta and surround the heart making sure it gets the oxygenated blood it needs)
What is wrong when you have coronary heart disease and how can you treat it
- fatty deposits clog arteries that supply blood to the heart
- stent: mesh tube inserted into the artery to open the artery wider as it swishes fatty deposit onto the outskirts of the arteries instead of the middle
(RISK: BLOOD CLOTTING AFTER INSERT) - Statins - a drug that lowers blood cholesterol levels slowing down the build up of fatty deposits, also lower the risk of some diseases
(RISK: NEED TO REMEMBER TO TAKE THEM AND CAN HAVE SOME SERIOUS SIDE EFFECTS)
What is wrong if you have faulty valves and how can you fix them
valves aren’t opening properly or are leaky which means blood will flow from both directions meaning less oxygenated blood will be reaching the tissues f the body, effects usually are short breath and fatigue - cells aren’t receiving enough oxygen = CAN RESULT IN DEATH
- mechanical valves
pros: last forever
cons: patients need to take medicine to prevent clotting - biological valves
pros: no medication
cons: only last 10-15 yrs
How to treat heart failure
ultimately needs a heart transplant from a donor but for temporary survival can use an artificial heart while waiting for a donor
6 causal mechanisms of non-communicable diseases
- cardiovascular disease
- type 2 diabetes
- liver & brain damage
- lung disease & cancer
- damage to foetus
- cancer
what’s the difference between benign tumors and malignant tumors
benign:
- 1 area of the body
- don’t spread
- can put pressure on other organs therefore damaging them
malignant:
- small parts of tumor can break off and spread through blood
- they can cause secondary tumors
- difficult to treat
2 ways to treat cancer
Radiotherapy:
- uses radiation to kill cancer cells but can also harm healthy cells
Chemotherapy
- chemical drug that halts mitosis in rapidly dividing cells like cancer cells and hair cells
Risk factors for cancer
- obesity
- smoking & drinking
- viruses
- genetics
Xylem:
- what does it transport
- in what direction
- is energy needed?
- water & minerals
- upwards only
- no because it is a physical process
Phloem:
- what does it transport
- in what direction
- is energy needed?
- dissolved food (glucose)
- up & down
- yes
What do guard cells control
gas exchange
What is transpiration
- water evaporates from the surface of cells in the air spaces of the spongy mesophyll
- water vapour leaves through the open stomata
What is a transpiration stream
- water is pulled up from the xylem to replace lost water
- more water is taken up by the roots
During the day, many potassium ions enter the guard cells, explain how this helps the plant carry out photosynthesis
if many potassium ions enter the guard cells it increase their concentration inside the cell, making it higher than outside the cell. water will move by osmosis from the area of lower potassium ion concentration to the area of higher potassium ion concentration. this movement of water into the guard cell causes them to change shape opening the stomata. This allows CO2 to diffuse into the leaf where itis used for photosynthesis.
Factors affecting photosynthesis
- light
- temperature
- humidity
- wind
what adaptations do plants have for when they are in unfavourable conditions
- thick waxy cuticle = waterproof = prevents water loss
- Wilting = reduces S.A. for transpiration + less sunlight on leaves
- Close the stomata = prevents photsynthesis
how are sieve tubes and companion cells adapted to their function
sieve tubes - have no nuclei and are specialised for transport
companion cells - One or more companion cells attached to each sieve tube provide this energy. A sieve tube is completely dependent on its companion cell(s)
what is the name of the process that moves dissolved sugars through phloem tissue
translocation
