Topic 2 Organisation Flashcards
What is a catalyst?
Substance that increases speed of reaction without being changed/used up in reaction
What do carboghydrases break down carbohydrates into?
Simple sugars
What is an example of a carbohydrase that breaks down starch?
Amylase
Which 3 places is amylase made in?
Salivary glands
Pancreas
Small intestine
Which 3 places are proteases made in?
stomach
Pancreas
small intestine
Which 2 places are lipases made in?
pancreas
Small intestine
What are the products of digestion used to make?
New carbohydrates, lipids and proteins
Where is bile made?
In the liver
Where is bile stored?
In the gall bladder
Where is bile released into?
Small intestine
How does bile neutralise Hydrochloric acid from the stomach?
Bile is alkaline
How does emulsifying fats increase the rate of fat breakdown by lipase?
Forms small droplets- larger surface area
Which solution is used to test for sugars?
Benedict’s
Which solution is used to test for starch?
Iodine
Which solution is used to test for protein?
Biuret reagent
Which solution is used to test for lipids?
Sudan 111
Where does gas exchange happen in the body?
Between Alveoli and blood in capillaries
Where are the lungs located in the body?
In the thorax (top part of body)
What are the lungs surrounded by?
Pleural membranes
What two tubes does the trachea split into?
Bronchi (each one is a bronchus to each lung)**
What smaller tubes to the bronchi split into?
Bronchioles
What happens to oxygen when the blood reaches body cells?
Oxygen released from red blood cells and diffuses into body cells
What happens to carbon dioxide when blood reaches body cells?
Carbon dioxide diffuses out of body cells into blood and carried back to lungs
Why is there a low concentration of oxygen and high concentration of CO2 in the blood passing next to the alveoli?
Blood has returned to lungs from rest of body
What unit should you calculate breathing rate in?
Breaths per minute (bpm)
What type of blood does the right ventricle pump?
Deoxygenated
Where does the right ventricle pump blood to?
Lungs to take in oxygen, blood then returns to heart
What type of blood does the left ventricle pump?
Oxygenated
Where does the left ventricle pump blood to?
All organs (other than lungs) and oxygen given to body cells
What are the walls of the heart mostly made up of?
Muscle tissue
What are the four chambers of the heart?
Right atrium
Right ventricle
Left atrium
Left ventricle
What are the names of 5 blood vessels?
Aorta
Vena cava
Pulmonary artery
Pulmonary vein
Coronary artery
Which 2 blood vessels does the blood flow into the 2 atria from?
Vena cava and pulmonary vein
How does the heart have its own supply of oxygenated blood?
Coronary arteries branch of aorta and surround heart
What is your resting heart rate controlled by?
group of cells in right atrium that act as a pacemaker
What does the hearts pacemaker do?
Produces small electrical impulse which spreads to surrounding muscle cells, causing them to contract
What is used to control heartbeat if the natural pacemaker cells don’t work properly/irregular heartbeat?
Artificial pacemaker
How does an artificial pacemaker work?
Little device implanted under skin that has a wire going to heart, produces electric current to keep heart beating regularly
What is the function of the arteries?
carry blood away from heart
What is the function of the capillaries?
Involved in exchange of substances at tissues
What is the function of the veins?
Carry blood to heart
What makes the artery walls strong and elastic?
Contain thick layers of muscle and elastic fibres
Why are artery walls strong and elastic?
Heart pumps blood out at high pressure
How are capillaries adapted so that substances can diffuse in and out of them?
Permeable walls
How thick are capillary walls?
One cell thick
How does the capillaries having thin walls increase the rate of diffusion?
Decreases diffusion distance
How are capillaries able to exchange surfaces with body cells?
Carry blood very close to every cell in body
Why are the vein walls less thick than artery walls?
Blood is at a lower pressure
What do veins have to keep blood flowing in the right direction?
Valves
What is blood?
Tissue consisting of plasma, in which white blood cells, red blood cells and platelets are suspended
What is the shape of a red blood cell that gives it a large surface area?
Biconcave disk
What is the red pigment red blood cells contain called?
Haemoglobin
What are platelets?
Small fragments of cells with no nucleus
What do white blood cells have that red blood cells don’t?
Nucleus
What is plasma?
Pale straw-coloured liquid that carries everything in blood
What does coronary heart diseases cause?
Lack of oxygen to heart muscle (can result in heart attack)
What is a stent?
Wire mesh tube
What do statins do?
Reduce blood cholesterol levels - slows down rate of fatty deposits forming
What are 2 advantages of stents?
- effective for long time
- quick recovery time from surgery
What are 2 disadvantages of stents?
- risk of complications during operation eg heart attack
- risk of infection from surgery
What are 2 advantages of statins?
- reduce risk of strokes, heart attacks, coronary heart disease
- can increase beneficial type of cholesterol in bloodstream
What are 2 disadvantages of statins?
- long-term drug, must be taken regularly
- can cause negative side effects
What are 2 ways heart valves can become faulty?
- become unable to open properly
- become leaky
What are the consequences of having faulty valves?
Blood doesn’t circulate as effectively
How can severe valve damage be treated?
By replacing valve
What are the 2 types of replacement valves?
biological valves (from humans or mammals)
mechanical valves (man-made)
What is a risk of valve replacement surgery?
Blood clots
What are 2 uses of artificial hearts?
- temporary fix to keep patient with heart failure alive until donor heart found
- allow heart to rest to aid recovery
What is the main advantage of artificial hearts?
less likely to be rejected by immune system than donor heart
What are 2 disadvantages of artificial hearts?
- don’t work as well as healthy natural ones (parts could wear out or electric motor fail)
- patient has to take drugs to thin blood (prevent blood clots)
What can different types of diseases do?
Interact and cause other issues
What are people with defects in their immune system more likely to suffer from?
Infectious diseases
What can some types of cancer be triggered by?
Certain viruses living in cells
What can immune system reactions caused by a pathogen trigger?
Allergic reactions such as skin rashes or worse asthma symptoms
What can be triggered when someone is suffering from severe physical health problems?
Mental illness/depression
What are things that cause cancer known as?
Carcinogens
What is an example of a carcinogen?
Ionising radiation
What is cancer caused by?
Changes in cells that lead to uncontrolled growth and division causing formation of tumour
What is a benign tumour?
Grows in one place (usually within a membrane), does not invade other parts of body
Describe a malignant tumour (3 things)?
Invade neighbouring tissues
spread to other parts of body in bloodstream
cancer cells can detach and form secondary tumours
What are 4 lifestyle risk factors for various types of cancer?
Smoking
Obesity
UV exposure
Viral infection
What are the 6 plant tissues?
Epidermal
Palisade mesophyll
Spongy mesophyll
Xylem
Phloem
Meristem tissue
What does the epidermal tissue do?
Covers whole plant
What is the epidermal tissue covered with?
Waxy cuticle
What does the waxy cuticle do?
Reduces water loss by evaporation
Why is the upper epidermis transparent?
So light can pass through to palisade layer
Why does the spongy mesophyll tissue contain big air spaces?
Allow gases to diffuse in and out of cells
Where is meristem tissue found?
Growing tips of shoots and roots
What is meristem tissue able to do?
Differentiate into different types of plant cell- plant growth
What do stomata do?
Allow CO2 to diffuse directly into leaf
Where are the stomata located?
In lower epidermis
What do the roots, stem and leaves form?
Plant organ system for transport of substances around plant
What are the phloem composed of?
Tubes of elongated living cells
Why do phloem cells have small pores in their end walls?
Allow cell sap to flow through
What is cell sap?
Liquid made up of water and substances being transported
What do phloem transport?
Dissolved sugars from leaves
Where do the phloem transport dissolved sugars to?
Rest of plant for immediate use or storage
What is translocation?
Movement of food molecules through phloem
What direction do phloem transport substances in?
Up and down plant
What do the xylem transport?
Water and mineral ions from roots
Where do the xylem transport to?
Stem and leaves
What is the transpiration stream?
Movement of water from roots, through xylem and out of leaves
What are the xylem tubes composed of?
Dead cells with no end walls between them and hole down middle
What are the xylem strengthened with?
Lignin
What is transpiration caused by?
Evaporation and diffusion of water from plants surface
Where does most transpiration happen at?
Leaves
What does water evaporating from the leaf create?
Slight shortage of water in leaf
What happens when there is a slight shortage of water in the leaf?
More water drawn up from rest of plant through xylem to replace it
What is there a constant stream of through the plant?
Transpiration
What do root hair cells take in water using?
Osmosis
What do root hair cells take in minerals using?
Active transport
Why do root hair cells have to use active transport to absorb minerals?
Concentration of minerals higher in root hair cell than in soil
What gives root hair cells a large surface area?
Cells on plant roots grow into hairs that stick out into soil
What is transpiration a side-effect of?
Way leaves are adapted for photosynthesis
Why does water escape from the leaves through the stomata by diffusion?
More water inside plant than in air outside
What are the 4 things that affect the rate of transpiration?
Temperature
Light intensity
Humidity
Air flow
How does light intensity affect the rate of transpiration?
Brighter light, greater transpiration rate
Why is the transpiration rate lower when it’s dark?
Stomata close (no photosynthesis)- very little water can escape
How does temperature affect the rate of transpiration?
Warmer, faster transpiration
Why is the rate of transpiration higher when it’s warmer?
Water particles have more energy to evaporate and diffuse out stomata
How does air flow affect the rate of transpiration?
Better air flow around leaf (stronger wind), greater transpiration rate
Why is there a higher rate of transpiration when there is good air flow?
Water vapour swept away- low concentration of water in air outside leaf
How does humidity affect the rate of transpiration?
Drier air around leaf, faster transpiration rate
How can you estimate the rate of transpiration?
Measure uptake of water by plant (directly related to water loss by leaves)
What 2 substances diffuse out through the stomata?
Water vapour
Oxygen
Where does carbon dioxide go after diffusing into the stomata?
Diffuses into cells for photosynthesis
What are the size of the stomata controlled by?
Guard cells
What are 2 ways the leaf is adapted to be an exchange surface?
Flattened shape- increase surface area
Air spaces inside leaf- increase surface area
What shape are guard cells?
Kidney shaped
What do guard cells do when the plant has lots of water?
Guard cells fill with water, go plump and turgid so stomata open
What do guard cells do when the plant is short of water?
Guard cells lose water, become flaccid so stomata close
What do guard cells have to make the opening and closing work?
Thin outer walls and thickened inner walls
Why are guard cells sensitive to light?
Close at night to save water without losing out on photosynthesis
