Organisation Flashcards
What is a tissue?
A tissue is a group of similar cells that work together to carry out a particular function
Examples of tissues
Muscular tissue - contracts to move whatever it’s attached to
Glandular tissue - makes and secretes chemicals like enzymes and hormones
Epithelial tissue - covers some parts of the human body e.g. the inside of the gut
What is an organ system?
An organ system is a group of organs working together to carry out a particular function
Example of an organ system
Digestive system - glands (pancreas and salivary glands) stomach, liver, small intestine and large intestine
Why can enzymes be described as biological catalysts?
They speed up useful chemical reactions in the body
Why do enzymes only usually catalyse one reaction?
Their active site is only complimentary to one type of substrate
What does it mean when an enzyme is denatured?
Its active site has changed shape due to intense heat or acidic conditions
Where is amylase found?
It’s made in the salivary gland and the pancreas and it works in the small intestine
What is the role of lipases?
They break down lipids into fatty acids and glycerol
Where is bile made and stored?
It’s made in the liver and stored in the gall bladder
What does bile do?
It emulsifies fats into smaller, more soluble pieces which gives the fat a bigger surface area for lipase to work on. It also neutralises the stomach acid to make the conditions alkaline, therefore the enzymes can work in the small intestine
What are organs?
Organs are groups of tissues that work together to perform certain functions
What are the tissues in the stomach and what do they do?
Muscular tissue - moves the stomach wall to churn up the food
Glandular tissue - makes digestive juices to digest food
Epithelial tissue - covers the inside and outside of the stomach
What is the name of the substance when a substrate fits into the enzyme’s active site?
Enzyme substrate complex
What is the name of the substance when the enzyme’s active site has turned the substrate into two products?
Enzyme product complex
What is the optimum pH for enzymes?
The pH level that they are most active at. E.g., pepsin has an optimum pH of 2
What does amylase break down?
It catalyses the breakdown of starch to maltose
What do carbohydrases break down?
Carbohydrates into simple sugars
What do proteases break down?
Proteins into amino acids
Where are proteases found?
They’re made in the stomach (called pepsin here) and the pancreas and found in the small intestine
Where are lipases found?
They’re made in the pancreas and work in the small intestine
Name three substances and what they test for
Benedict’s Test - testing for sugars - goes red
Iodine solution - tests for starch - goes blue-black
Biuret Test - tests for proteins - goes purple
What do the salivary glands do?
They produce amylase in the saliva
What does the stomach do?
-It pummels the food with its muscular walls
-It produces pepsin
-It produces hydrochloric acid to kill bacteria and give the right pH for pepsin to work