Organisation Flashcards
What is digestion? (2)
It is a process during which mechanical and chemical breakdown of large insoluble food particles are broken down into smaller, soluble food particles so that they can be absorbed into the bloodstream.Digestive enzymes help to break down the large food molecules.
Mechanical digestion involves
biting, grinding, chewing, mixing (mastication)
Chemical digestion involves
It is the breakdown of larger food particles into smaller soluble food particles by digestive enzymes.
What is an enzyme?
- It is a biological catalyst
- It is a protein molecule
- It speeds up chemical reactions without undergoing only permanent chemical change
ENzymes, hormoNes and aNtibodies are all
proteins
Name the 3 enzymes
Protease, Amylase, Lipase
Protease
Breaks down large insoluble protein molecules into smaller, soluble amino acids (acts in an acidic medium).
AmyLase
It converts large insoluble starch molecules into smaller soluble sugar molecules eg: glucose, acts in an aLkali medium.
AmyLase
It converts large insoluble starch molecules into smaller soluble sugar molecules eg: glucose, acts in an aLkali medium.
Lipase
It converts insoluble lipids (fats) into soluble smaller fatty acids and glycerol (acts in an alkali medium).
Whar organs are the enzymes (PALs) found in?
- small intestine
- pancreas
- aMylase: found in the Mouth –> salivary amylase
State the factors that effect the efficient functioning of an enzyme (STEP^2PS)
Substrate concentration Temperature Enzyme concentration PH Pressure Surface area
What are the differences between (U)secrete and (W)eXcrete?
secrete - useful substances are released
eXcrete- Wate products/ substances are removed from the body eg: CO2, urea into urine, excess water vapour, H2O (g), faeces (egestion)
Describe the process of digestion
- After masticating, the food is in the form of a ‘ball’, bolus
- The bolus is ‘forced down’ by muscular contractions called peristalsis (oesophagus)
- Liver- it secretes biLe- Bile is an alkalie, it neutralises stomach acid (HCL) (aq). It emulsifies fats, increases the surface area to volume ratio- larger molecules are broken down to smaller molecules. It provides an alkali medium for amylase and lipase to functions.
- stomach- secretes hydrochloric acid (HCL)–>it kills bacteria, it provides an acid medium for protease to act efficiently.
- Gall bladder- stores bile and releases when needed
- pancreas-secretes the digestive enzymes as well as hormONes, insulin, glucagON.
- small intestine is approximately 6-8 m (ileum) - maximum absorption of soluble food particles (secretes digestive enzymes= PALs)
- large intestine absorbs water
What does a large SAVR help organisms to do?
To absorb, gaseous exchange, diffusion, photosynthesis, respiration
