B3 Organisation And Digestion Flashcards
Organelle
Smaller parts or a cell
Tissue
A group of cells the same type
Organ
Group of cells working together
Organ system
Group of organs that work together to perform one or more functions
Examples of cells
Blood cells
Stem cells
Sperm cells
Examples of tissues
Epithelial tissue, glandular tissue, nervous tissue
Examples of organs
Brain, lungs, heart
Name all the organs in digestive system
Mouth, esophagus, stomach, small intestine, large intestine, rectum and anus
Function of mouth
Food is broken down into smaller pieces by chewing
Function of oesophagus (gullet)
Food travels down from mouth to stomach
Function of gallbladder
Where bile is stored before released into small intestine
Function of large intestine
Excess water is absorbed from the food
Function of small intestine
Breaks down nutrients
Absorbs nutrients
Gets rid of unnecessary components
Function of liver
Bile in the liver neutralises stomach acid and emulsify fats
Function of pancreas
Protease, lipase and amylase are released into the small intestine to help digest the food
Function of rectum
Where the faeces are stored before passed out of the anus
Example of food molecules which are polymers
Proteins polymers of amino acids and nucleic acid
Tissues that make up organs
Epithelial tissue
Connective tissue
Muscle tissue
Nervous tissue
How the small intestine is adapted to its function
Villi and microvilli that increase surface area
Why the cells of multicellular organisms are organised into tissues, organs and organ systems
To support the life processes of cells to keep the organism alive
Function of Epithelial tissue
Helps protect the stomach from the harsh acidic environment
What does potato contain
Starch, lipids, sugar, protein
Starch
What does vegetable oil contain
Starch, lipids, sugar, protein
Lipids
Do egg whites contain
Starch, lipids, sugar, protein
Sugar
Protein
Does a banana contain
Starch, lipids, sugar, protein
Sugar
Protein
Starch test
Few drops of iodine on food solution
If solution turns blue-black starch is present
Lipid test
Few drops of ethanol to food solution
If solution turns cloudy food has lipids
Sugar test
Few drops of benedict’s to food solution
If solution turns green the food contains some sugar
If orange-red the food contains lots of sugar
Protein test
Few drops of biuret to food solution
If purple contains protien
Enzymes
Proteins which act as biological catalysts
Function of enzyme in the body
Speeds up rate of chemical reaction
What affects how well an enzyme works
Temperature and pH
How are enzymes used in digestion
To break down food molecules
What do carbohydrates, proteins and lipids break down to
Carbohydrase
Protease
Lipase
How to test for substrates and products in the model gut
Set up Visking tubing
Fill with mixture of starch and glucose
Suspend in boiling tube for period of time
How some organisms can survive in extreme conditons
Enzymes enable these organisms to function in extreme conditions
How a change in temperature or pH affects the rate of an enzyme-catalysed reaction
If pH is too high or too low the pH interferes with the bonds holding the enzyme together
This changes the shape of the active site and denatures the enzyme.
Raising temp increases reaction lowering temp decreases
How enzymes speed up reactions
Reducing the activation energy increasing the rate of reaction
How enzymes control metabolism
Enzymes lower the activation energies of chemical reactions
Use the ‘lock and key theory’ to explain why the shape of the enzyme is vital for it to function
The substrate fits perfectly into the enzyme’s active site
Why high temperatures and changes in pH prevent enzymes from catalysing reactions
High temperatures will break these forces
What does stomach contain
Acid
Where is bile produced
Liver
Function of bile
Bile breaks up fats into tiny droplets, through a process called emulsification
How bile increases the efficiency of fat digestion
Increases the rate of the lipase-catalysed reactions that break fats down
The tiny droplets have a higher surface area than the original fat drop
How acid in the stomach increases the efficiency of pepsin
A low pH (1.5 to 2) activates pepsin
How the rate of an enzyme catalysed reaction shows how efficient the reaction is
The less substrate they need to reach half of their maximum speed, the more efficient they are
If Km is low enzyme is efficient
Why the cells of multicellular organisms are organised into tissues, organs, and organ systems
Maintain the internal environment, keeping it steady and able to provide for the needs of the cells
Structure of starch
Composed of long chains of glucose
Structure of simple sugar
6 carbons
12 hydrogens
6 oxygens joined together through covalent bond
Hydrogens not at all bonded with oxygen
Structure of lipids
A glycerol molecule and three fatty acids bonded together
Structure of protein
Polymers of amino acids, formed by long chains of amino acids joined together by peptide bonds
How to carry out food tests
Break up the food using a pestle and mortar
Transfer to a test tube and add distilled water
Mix food with water by stirring with a glass rod
Filter the mixture using a funnel and filter paper, collecting the solution
Check the colour of solution depending if there’s sugar or not
Function of carbohydrates
Source of energy
Function of protein
Growth and repair
Function of lipids
They help with moving and storing energy
Plan experiment to investigate how different catalysts affect the rate of a reaction
Add hydrogen peroxide into a conical flask
Use delivery tube to connect this flask to a measuring cylinder upside down in water trough
Add chosen catalyst into conical flask and close bung
Measure volume of gas produced in a fixed time using the measuring cylinder
How to draw a tangent to a line and calculate the rate of a reaction with guidance
Draw a tangent to the curve at time = 0
This is the line drawn in red
Make tangent as large as possible
Calculate gradient of tangent = change in y/change in x
This equals the initial rate
How to calculate the mean rate of an enzyme-catalysed reaction
Rate = change ➗ time
Rate = amount of substrate used ➗ time
Function of muscular tissue
Contracts to move whatever its attached to
Function of glandular tissue
Makes and secretes chemicals like enzymes and hormones
Cells
Basic building blocks that make up all living organisms
What do muscular tissue, glandular tissue and epithelial tissue do in organ system
Muscular tissue - moves stomach wall to churn up food
Glandular tissue - makes digestive juices to digest food
Epithelial tissue - covers the outside and inside of the stomach
How would you usually make a resction happen quicker
Raising temperature
Catalyst
A substance which increases the speed of a reaction, without being changed or used up in the reaction
True or false
Enzymes usually only catalyse one specific reaction
True
How does enzyme do fit in substrates
Active site changes shape a little as substrate binds to it to get a tighter fit
At what pH does pepsin enzyme works best at
2 as it’s well suited to the acidic conditions