B2- Organisation.enzymes and circulation

Topic 2a

What is an enzyme? 

A Biological catalyst that speeds up chemical reactions without being changed or used up in the process

• What are the types of blood vessels?

Arteries

Cappilaries

Veins

What is the role of the arteries and their structure?

They carry blood away from heart

They have thick muscle tissue and a small lumen and elastic wall

What is the role of the cappilaries and their structure?

Receives blood from arteries

1 cell thick. permeable walls

Whatis the role of Veins and their structure?

Carry blood to heart

Thin muscle tissue, big lumen

How does gas exchange happen in the alveoli?

• Tiny air sacs surrounded by blood cappilaries: alveoli!

• Oxygen diffuses OUT OF ALVEOLI (into blood)

• CO2 moves from blood to alveoli (to be breathed out)

• Oxygen is released from rbc to body and at the same time CO2 diffuses from body cells-blood-lungs

What is the hearts pacemaker?

Resting heart rate is controlled by a group of cellsin the right atrium wall producing electric impulse= pacemaker

What is a catalyst? 

A substance that increases the speed of a reaction without being changed or used up

What is the active side?

Has unique shape  that fits onto substance involved in specific reaction 

What is a substrate? 

Joins onto the enzymes active side, catalysing reaction (complimentary shape) 

What is optimum?

The temperature or PH at which the enzyme works best at

What happens if temperature increses rate of reaction, getting too hot? 

Bonds holding enzyme together break and becomes denatured

What happens if the PH gets too high or low? 

It damages binds in the enzymes, chnaging shape of active site (denatured) 

If starch is present what colour will iodine change? 

Browny-orange TO blue-black

How do you calculate rate of reaction?

How much something changes over time: Rate= 1000÷ time
If experiment measure how much something chnages over time: Rate= Change÷time taken

Why can't starch, proteins and fats pass through the digestive system? 

They are BIG molecules, so digestive enzymes BREAK them into smaller soulable ones! (so they can be absorbed into the bloodstream)

What are the 3 digestive enzymes?

• Amylase- starch into glucose/maltose

• Protease- proteins into amino acids

• Lipase-lipids into glycerol and fatty acids

What is bile and its function? 

Bile is made in the liver and stored in the gall bladder its is ALKALINE to neutralise hcl and emulsifies fat into droplets!! (bigger surface area for lipase to increase rate of fat breakdown) 

What do the products of digestion make? 

They can be used to make new carbohydrates, proteins and lipids

Where does the air that we breathe go? 

Throght the trachea, splits into tubes called bronchi thats split into smaller tubes called  broncioles that end at smakl air sacs called avleoli

What results do you get from The Benedicts test (Sugar)

If food sample contains sugar it wil go from blue- green/yellow/red depending on how much sugar is in the food

What results do you get from the biuret test? (protein)

If food contains protein it goes from blue to purple

How are the lungs adapted for gas exchange?

Through tiny air sacs called alveoli

How are alveoli adapted for gas exchange?

• large surface area- CO₂  and O diffuses at same time

• Thin walls- short diffusion distance

• Moist lining- gases dissolve quicker- faster diffusion

What do red blood cells do?

Carry oxygen from lungs to all cells in the body

What shape does a red blood cell have?

Bioconcave shape, large surface are to carry more oxygen

What does haemoglobin do?

Binds to oxygen to become oxyhaemoglobin

What does white blood cells do

• Defend against infection by:

• Changing shape and engulfing microorganisms

• Producing antibodies

What do platelets do?

Small fragments of cells that help blood clot

What does plasma do?

Carries everything in blood

What does plasma carry?

• RBC

• WBC

• Hormones

• Proteins

• Glucose