Revision cards Flashcards
What are cells?
Cells are the fundamental units (building blocks) of all living organisms
What are tissues?
Tissues are groups of similar cells that act harmoniously to perform a similar function
What are organs?
Organs are groups of distinct tissues that work together to perform a specific function
What are organ systems?
Organ systems are groups of organs that work together to perform a particular role
What are organisms?
Organisms are the highest level of organisation in a multicellular organism consisting of several organ systems
Which tissue covers the inside and the outside of an organ?
Epithelial tissue
Which tissue churns food and digestive juices of the stomach together?
Muscular tissue
Which tissue can contract to bring about force and motion?
Muscular tissue
Which tissue produces the digestive juices that break down food?
Glandular tissue
Which tissue is capable of photosynthesis?
Mesophyll tissue
Which tissue includes skin in humans and the waxy covering of some plants?
Epidermal tissue
What is the role of the stomach?
To digest food
What is the role of the small intestine?
To digest food and absorb nutrients
What is the role of the large intestine?
To absorb water molecule and produce faeces
What is the role of glands in digestion?
To produce digestive enzymes
What is the role of the liver?
To produce bile
Name 3 of the tissues in the stomach
Muscular - contracts to move stomach contents around for digestion
Glandular - produces digestive juices that break down stomach contents
Epithelial - lines stomach to protect it from harsh environment
To catalyse (speed up) a reaction, what must bind to what?
The reacting chemical (substrate) must bind to the enzyme’s active site.
What is the equation for the rate of reaction?
Rate of reaction = change in mass/ change in time
Increasing the ___________ of a working enzyme initially increases the ________.
Enzymes have an _______ temperature and, once this is reached, the activity _________.
Then, last a certain ___________, the ______ ____ changes shape, and the enzyme is _________.
Temperature
Activity
Optimum
Decreases
Temperature
Active site
Denatured
What do digestive enzymes do?
Digestive enzymes catalyse the breakdown of large, insoluble food molecules into smaller, soluble (can be dissolved) molecules that are then small enough to be absorbed into the bloodstream.
What are the three main digestive enzymes?
Amylase
Protease
Lipase
The main type of carbohydrate is starch.
What is starch broken down by?
Amylase
What is starch broken down into?
Maltose (and other sugars)
Where is amylase made?
Small intestine
Pancreas
Salivary glands
_____________ break carbohydrates down into sugars.
Amylase is a type of ____________ that breaks down starch in our bodies.
Carbohydrases
Carbohydrase
What are proteins broken down by?
Proteases (digestive enzymes)
What are proteins broken down into?
Amino acids
Where are proteases made?
Small intestine
Pancreas
Stomach (pepsin)
Where is pepsin?
What does it do?
Pepsin is a stomach enzyme that helps to break down / digest proteins
What are lipids broken down by?
Lipases
What are lipids broken down into?
Glycerol
Fatty acids
Where is lipase produced?
Small intestine
Pancreas
Describe how bile emulsifies fats
Bike breaks up fats (like oil) into tiny droplets, through a process called emulsification.
The tiny droplets have a higher surface area than the original fat drop, which increases the rate of the reactions (catalysed by lipase) that break fats down.
Describe how bile neutralises acid
Bike neutralises acid from the stomach to stop enzymes denaturing (losing activity).
What is bile?
An alkaline substance stored in the gallbladder after being made in the liver. Enzymes in the small intestine operate best in alkaline conditions, so bile helps to do this
What reagent is used to test for Starch?
Iodine
What reagent is used to test for Lipids?
Sudan III
What reagent is used to test for Proteins?
Biuret
What reagent is used to test for Sugars?
Benedict’s
What colour will the iodine solution turn if starch is present?
Blue-black
What colour will the Benedict’s solution turn if sugar is present?
Small amount present = green
More sugar present = yellow
A lot of sugar present = brick red
What colour will a biuret solution turn if proteins are present?
Purple
What colour will Sudan III solution turn if lipids are present?
red-stained oil layer will float on the water surface
If ethanol = white colours emulsion
Arteries do what?
Transport blood away from the heart
Veins do what?
Carry blood towards/ into your heart