Animal tissues, organs and organ systems (2.2) (M) Flashcards
What does the breakdown of starch produce?
smaller sugars (e.g. sucrose/glucose)
What is the digestive system?
an organ system in which several organs work together to digest and absorb food.
What does the breakdown of lipids (fats) produce?
fatty acids and glycerol
What does the breakdown of protein produce?
amino acids
4 organs
Which organs do food pass through in the digestive system?
- oesophagus/gullet
- stomach
- small intestine
- large intestine
What is the function of the mouth in the digestive system?
where food is entered (ingested) into gut, saliva mixes with food here
What is the function of the salivary glands in the digestive system?
where saliva containing amylase is produced and released
What is the function of the oesophagus/gullet in the digestive system?
this muscular tube moves ingested food into the stomach
What is the function of the stomach in the digestive system?
this muscular organ holds food whilst being mixed with pepsin (example of protease) and contains HCL
What is the function of the liver in the digestive system?
produces bile
What is the function of the gallbladder in the digestive system?
stores bile before being released into small intestine
What is the function of the pancreas in the digestive system?
produces digestive enzymes
What is the function of the small intestine in the digestive system?
where food is mixed with bile and digestive enzymes and where absorption of food into blood occurs
What is the function of the large intestine in the digestive system?
where water is reabsorbed, faeces are stoned (created) and released
What are enzymes?
Large proteins that act as biological catalysts, speeding up the rate of reactions in living organisms
What do enzymes do?
Speed up the rate of reactions involved in metabolism
Describe the ‘lock and key’ of enzyme action
Enzyme binds/fits to substrate because they have complimentary shapes
so substrate broken down into products
when bonds within substrate are broken
so products are released or enzyme not changed
How do enzymes bind to substrates?
Every enzyme has its own unique active site, and it’s the specific shape of this active site that allows the enzyme to bind to its specific substrate (complimentary shape).
Explain why enzymes will not work with all substrates?
Each active site has a specific shape
Enzymes will only bind to one specific substrate, so if the substrate doesn’t fit the active site (not a complimentary shape), the chemical reaction won’t be catalysed
How are the nature of enzyme molecules related to increased temperature (above optimum)?
increasing the temperature increases the rate of an enzyme-controlled reaction until it gets so hot that some of the bonds holding the enzyme together break and the enzyme becomes denatured, so the active site no longer fits the substrate.
How are the nature of enzyme molecules related to extreme pH?
extreme pH changes can denature enzymes
(the bonds holding the enzyme together break, so the active site no longer fits the substrate)
Enzymes work best at (…) temperate and pH and this may (…) for different enzymes
optimum
vary
What is often optimum temperature for enzymes in the human body?
37oC
What is the role of digestive enzymes?
to convert large insoluble molecules of food into small soluble molecules that can be absorbed into the bloodstream
Which enzyme converts carbohydrates into simple sugars?
carbohydrase
Which do carbohydrases do?
break down carbohydrates to simple sugars
Where are carbohydrases produced?
salivary glands, pancreas and small intestine
Where do carbohydrases work?
the mouth and small intestine
Which carbohydrase breaks down starch?
Amylase
What do proteases do?
break down proteins to amino acids
Where is protease produced?
Stomach, pancreas and small intestine
Where do proteases work?
Stomach and small intestine
What do lipases do?
break down lipids (fats) to glycerol and fatty acids
2 uses
What are the products of digestion used to do?
- used to build new carbohydrates, lipids and proteins
- some glucose is used in respiration
Where is bile produced and where is it stored?
Bile is made in the liver and stored in the gall bladder
to be released into small intestine
Is bile acidic or alkaline?
alkaline
Why is bile being alkaline useful?
neutralise hydrochloric acid from the stomach so it can reach optimum pH
What else does bile do other than neutralising HCl from stomach?
emulsifies fats (fat globules) to form small droplets which increases the surface area to increase the rate of fat breakdown by lipase.
What do the alkaline conditions and large surface area of fat after mixing with bile do for fat breakdown?
increase the rate of fat breakdown by lipase
Is bile an enzyme?
No
What are the two main types of carbohydrates?
simple sugars (e.g. glucose) and starch (which is made up of chains of simple sugars)
What are proteins made up of?
long chains of amino acids
What are lipids (fats and oils) made up of?
fatty acids and glycerol
What is the heart and what is its function?
a muscular organ that pumps blood around the body in a double circulatory system
Describe the structure of the heart (left and right ventricle)?
The right ventricle pumps blood to the lungs where gas exchange takes place.
The left ventricle pumps blood around the rest of the body.
Label the heart