Organisation (paper 1)

what are the three types of tissue?

* muscular
* glandular
* epithelial

what does epithelial tissue do?

covers some parts of the body eg. the inside of the gut

what does muscular tissue do?

contracts (shortens) to move whatever its attached to

what does glandular tissue do?

makes and secretes chemicals like enzymes and hormones

what three tissues do organs consist of?

* muscular
* glandular
* epithelial

what does muscular tissue do in the stomach?

moves the stomach to churn up food

what does glandular tissue do in the stomach?

makes digestive juices to digest food eg. enzymes

what are cells?

basic building blocks that make up all living organisms

what are enzymes made up of?

large proteins made up of chains of amino acids

define an ‘induced fit’

the active site changes shape a little as the substrate binds to it to get a tighter fit

what happens to enzyme if the pH is too high or low?

the pH interferes with forces holding amino acids together to make the protein so the shape of the active site changes caused enzyme to denature

define denature

when an active site denatures so that the substrate doesn’t fit anymore

define emulsify?

breaks

what is the job of bile?

it neutralised stomach acid and emulsifies fats

how does bile help enzymes do their job?

provides a larger surface area of fat for lipase to work on so it’s digested faster

is bile an alkali or an acid?

alkali

give examples of large insoluble food molecules

* lipids
* carbohydrates
* proteins
* starch

examples of small soluble food molecules

* glycerol and fatty acids
* simple sugars
* amino acids
* maltose

which enzyme is amylase the same as?

carbohydrase

where in the body is amylase produced?

* saliva
* small intestine
* pancreas

where is protease produced?

* stomach
* small intestine
* pancreas

where is lipase produced?

* pancreas
* small intestine

where is bile stored?

gall bladder

where is bile produced?

liver

where is hydrochloric acid produced?

stomach

what does hydrochloric acid do in the stomach?

* kills bacteria
* provides the right pH for protease to work

how do the alveoli do gas exchange?

* oxygen diffuses out of the alveolus into the blood
* carbon dioxide diffuses out of the blood into the alveolus to be breathed out

what’s a pacemaker in the heart?

groups of cells in the right atrium wall that control your resting heart rate and produce a small electrical impulse which causes muscles to contract

what does an artificial pacemaker do?

it produces an electric current to keep the heart beating regularly

where is an artificial pacemaker located?

under the skin and has a wire that connects to the heart

describe arteries

* blood travels at high pressure
* walls are thick
* lumen is narrow
* walls are strong but elastic

why are arteries so strong?

they contain thick layers of muscle to make them strong

how is it that arteries are able to stretch and spring back?

they contain elastic fibres

describe capillaries

* tiny
* permeable walls to substances can diffuse
* walls are one cell thick

how do capillaries being one cell thick effect the rate of diffusion?

increases the rate of diffusion by decreasing the distance over which it occurs

describe veins

* blood travels at low pressure
* walls are thin
* lumen is large
* contain valves

what do valves do?

keep blood flowing in the right direction so back flow isn’t a risk

describe the trachea

* strong but flexible
* has rings of cartilage

how does cartilage aid the trachea?

allows movement and flexion of the trachea during breathing but gives it support as well

what do white blood cells have that red don’t?

a nucleus

what pigment do red blood cells contain?

haemoglobin

what does oxygen and haemoglobin form in the lungs?

oxyhaemoglobin

what happens to oxyhaemoglobin in body tissues?

it splits into oxygen and haemoglobin to release oxygen to the lungs

define coronary heart disease

the coronary arteries that supply the blood to the heart get blocked by fatty deposits

describe the job of stents

they are tubes which are inserted inside arteries and keep them open

what are the advantages of stents?

* recovery time is quick
* lowers the risk of a heart attack
* they are effective for a long time

what are the disadvantages of stents?

* risk of infection
* may be complications during surgery eg. blood clot

what’s the job of statins?

used to reduce cholesterol in the bloodstream which slows down the rate of fatty deposits forming

what is cholesterol?

a type of lipid

what can too much cholesterol cause?

fatty deposits in arteries which leads to coronary heart disease

what are statins?

they are drugs

what are the advantages of statins?

* reduce the risks of strokes and heart disease
* reduces cholesterol levels in the blood
* easy to take
* low cost

what are the disadvantages of statins?

* must be taken regularly risk of being forgotten

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* can cause negative side effects like headaches, liver damage, kidney failure

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* it takes time for effect to kick in

explain why heart attack survivors get out of breath easily

heart can’t pump blood effectively meaning:

* less oxygen reaches muscles for respiration
* breathing rate increases to supply more oxygen
* breathing rate increases due to oxygen debt

what’s an artificial heart?

mechanical devices that pump blood who’s own heart has failed normally a temporary fix

what’s the advantage of an artificial heart?

less likely to be rejected by the body’s immune system

what is an artificial heart made of?

plastic or metal

what’s the. disadvantages of using an artificial heart?

* can lead to bleeding and infection

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* don’t work as well as natural hearts

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* can cause blood clots leading to strokes as blood doesn’t flow as smoothly

how can valves be damaged?

* heart attacks
* infection
* old age

what are biological valves?

valves that come from human or other mammals (pigs and cows)

what are mechanical valves?

valves that are man-made

what are the disadvantages of replacement valves?

can cause blood clots

what is artificial blood used for?

* used to replace the lost volume of blood lost

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* replaces the function of the lost red blood cells

what is artificial blood?

a blood substitute

how can faulty heart valves lead to poor circulation?

* may be leaky causing backflow
* valve may stiffen so it won’t open properly

define health

the state of physical, social and mental well being

what are are some factors that effect your health?

* your immune system
* cancer
* mental health
* balanced diet
* stress
* life situation (working with chemicals)

what’s a risk factor?

things that are linked to an increased likelihood that a person will develop a certain disease

what are communicable diseases?

diseases that can be spread from person to person

what are non communicable diseases?

diseases which can’t be spread/passed on

what’s a defective immune system?

your immune system is not able to fight off infections or viruses effectively

what is cancer caused by?

uncontrolled cell growth and division

what’s a tumour?

a mass of cells

where are benign tumours located?

within a membrane

what do benign tumours do?

* they stay in one place
* tumour grows until there’s no more room

are benign tumours cancerous?

no they don’t spread

are benign tumours dangerous?

no

what do malignant tumours do?

* tumour grows and spreads
* cells can break off from tumours and get into the bloodstream
* they invade healthy tissues and can form secondary tumours

are malignant tumours dangerous?

yes

are malignant tumours cancerous?

yes

why have the survival rates of cancer increased?

* improved treatments
* being bale to diagnose cancer earlier
* increased screening of the disease

what can smoking cause?

lung cancer

what are some factors that effect the chance of cancer?

* uv light exposure
* faulty genes
* smoking
* obesity

examples of plant organs

* stem
* roots
* leaves

epidermal tissue

* covers the whole plant
* transparent so light can pass through to palisade mesophyll

palisade mesophyll tissue

* where photosynthesis takes place
* contain chloroplasts

spongy mesophyll tissue

contain air spaces to allow gases to diffuse in and out of cells due to them being loosely packed

meristem tissue

where mitosis happens

waxy cuticle

reduces water loss, seals in water and makes plant virtually waterproof

what are phloem tubes made from?

elongated living cells with small pores in the end walls

what do the pores in a phloem allow?

allow cell sap to flow through so dissolved sugars water and salts

what do phloems do?

transport food substances, mainly dissolved sugars made in the leaves to the rest of the plant for immediate use or for storage

what way does food transport go in the phloem?

both directions

define translocation?

when substances move in both directions (up and down)

what are xylem cells made from?

* dead cells joined end to end
* no end walls
* have a whole in the middle

what is the material that strengthens xylem cells?

lignin

what do xylem cells do?

carry water and mineral ions from root to the stem and leaves

what’s transpiration stream?

* the movement of water from the roots through the xylem and out of the leaves

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* there’s a constant transpiration stream as more water is being drawn up

where does transpiration occur?

the leaves

why does transpiration happen?

a slight shortage of water in the leaf and so water is drawn up from the rest of the plant through the xylem