B2 - organisation Flashcards
The Thorax
The top part of the body
The abdomin
Lower part of the body
What separates the thorax from the abdomen
The diaphragm
Where does gas exchange happen
The alveoli
4 adaptations of the alveoli
- larger surface area
- moist lining - for dissolving gases
- good blood supply
- very thin walls - small diffusion pathway
How do you calculate breathing rate
Number of breaths
______________________
Number of minutes
Explain the transfer of oxygen and carbon dioxide between blood cells and body cells
Oxygen diffuses out from the blood cells into the body cells
Carbon dioxide diffuses out from the body cells into the blood cells
Explain the transfer of oxygen and carbon dioxide between the alveoli and blood cells
Oxygen diffuses out from the alveoli into the blood cells
Carbon dioxide diffuses out from the blood cells into the alveoli
How does the human body protect the lungs
Surrounded by pleural membranes and covered/ protected by ribcage
Function of the circulatory system
To get food and oxygen to every cell in the body and carry waste products like carbon dioxide and urea
2 waste products carried by circulatory system
Carbon dioxide and urea
3 examples of tissue and what they do( animsl£
- Muscular tissue - contracts to move
- glandular tissue - makes & secretes substances like enzymes
- epithelial tissue - covers some parts of the body
what tissues make up the stomach
Stomach
- muscular tissue
- glandular tissue
- epithelial tissue
what 5 organs make up the digestive system + what they do
Glands ( i.e pancreas & salivary glands)
- produce digestive juices
Stomach - where food is digested
Liver - produces bile
Small intestine - where food is digested and soluble food molecules are absorbed
Large intestine - where water is absorbed from undigested food
2 examples of glands and what they do in the digestive system
Pancreas and salivary glands
produce digestive juices
where is bile produced
the liver
small intestine
Where food is digested & soluble food molecules are absorbed into bloodstream
large intestine
Where water is absorbed from undigested food
theory used to explain function of enzymes
‘lock and key theory’.
2 adaptations of muscle tissue
- many mitochondria - energy for contraction
- special protein fibres which can change their length
purpose of muscular and glandular tissue in the stomach
- muscular tissue to churn food
- glandular tissue to release enzymes
3 main nutrients in food
- carbohydrates
- protein
- lipids
why must large molecules be digested
they are too large to be absorbed into the bloodstream and must be broken down
what happens during digestion (3)
- large molecules broken into smaller molecules by enzymes
- products of digestion absorbed into the blood stream
- products of digestion used to build new carbohydrates, proteins and lipids
steps of digestion (8)
- 1 food is chewed in the mouth + enzymes in saliva begin to digest starch into smaller sugar molecules
- 2 passes down the oesophagus into stomach + enzymes begin digestion of proteins + hcl in stomach also helps digest proteins
- 3 churning action of stomach muscles turns food into a fluid increasing surface area for enzymes to digest which passes into small intestine
- 4 pancreas releases enzymes that continue digestion of starch and proteins and starts digesting lipids
- 5 liver releases bile which neutralises stomach acid and speeds up digestion of lipids
- 6 in small intestine small food molecules are absorbed into the blood stream via diffusion or active transport
- 7 fluid goes to large intestine where water is absorbed
- 8 feces are released
enzymes in 2 words
biological catalysts
what are enzymes
large protein molecules with an active site on their surface where the substrate attaches to
how do enzymes break down molecules
- substrate fits perfectly into the active site as enzymes are specific
- enzyme breaks down substrate into the products
- ## if the substrate does not fit the the enzyme cannot break it down
what enzyme breaks down proteins
proteas
what are proteins
long chains of amino acids
what happens when we digest proteins
- protease enzyme converts protein back to the individual amino acids which are then absorbed in the bloodstream
- when amino acids are absorbed by body cells they join together in different order to make human proteins
what is starch
a chain of glucose molecules
what enzyme breaks down carbohydrates and starch specifically
carbohydrase breaks down carbs and amylase ( a type of carbohydrase) breaks down starch
what happens when carbohydrates are digested
we produce simple sugars
where is amylase found
- salivary glands
- pancreas
what is a lipid
a molecule of glycerol attached to three molecules of fatty acids
what enzyme breaks down lipids
lipase
what are lipids broken down to
glycerol and fatty acids
where is lipase found
- pancreas
- small intestine
what does bile do
help speed up reaction of lipids and neutralise stomach acid as it is alkaline ( note - not an enzyme )
how does bile speed up reaction of lipids
- bile emulsifies lipids (converts large lipid droplets into smaller droplets )
- this increases the surface area of lipid droplets
- increasing rate of lipid breakdown by lipase
what happens to enzyme activity as temperature increases
- rate of enzyme activity increases ( as the enzyme and substrate are moving faster - more successful collisions per second)
- continue to increase until enzyme reaches optimum temperature and works at fastest rate
- the activity will then rapidly decrease as the heat will cause enzyme to denature and the shape of the active site will change
issues with iodine test for starch
- only taking samples every 30 seconds meaning we only have an approximate time for reaction to complete
- solution - take samples at smaller interval i.e 10s
- colour change from orange to blue-black may not always be obvious as it tends to be gradual
- solution - have several ppl look at tile and decide when the reaction is complete
adaptations of small intestine for absorption
- long (around 5m) increasing surface area
- interior covered with millions of villi also increasing surface area
- microvilli on villi surface - surface area
- villi have good blood supply so bloodstream can rapidly remove products of digestion - increasing concentration gradient
- villi have thin membrane = short path
fish circulatory system
single circulatory system
- deoxygenated blood heart to gills oxygenated from gills to organs
Describe the human circulatory system
double circulatory system
- oxygenated from lungs to heart to organs
- deoxygenated blood from organs to heart to lungs
what separates the atrium from the ventricle
the valves
what is the heart
an organ consisting of mainly muscle tissue . pumps blood around the body made up of 4 chambers
where does the blood pass from heart to the lungs
the pulmonary artery
what type of blood passes from the lungs to the heart
oxygenated