Digestion and Enyzmes Flashcards
What is a cell?
Cells are the basic building blocks of all living organisms.
What is a tissue?
A tissue is a group of cells with a similar structure and function
What is an organ?
Organs are aggregations (group) of tissues performing specific functions.`
What is an Organ System?
Organs are organised into organ systems to perform a specific function
What is an Organism?
A group of organ systems working together
Give three examples of a cell.
any of : egg cell, nerve, root hair, epithelial, palisade, sperm, red blood cell
Give three examples of a tissue.
any of: muscle, blood, xylem, phloem
Give three examples of an organ.
any of: heart, stomach, leaf, flower, liver, lung
Give three examples of an organ system.
any of: digestive system, respiratory, root, shoot, circulatory
Give three examples of an organism.
any of: human, frog, dog, oak tree, orchid, snake
What is digestion?
It is a process where large molecules are broken down into smaller molecules to be absorbed into the blood.
What is the function of the mouth in digestion?
The beginning of the digestive system. Where food is broken apart and mixed with saliva that contains enzymes
What type of digestion happens in the mouth?
mechanical digestion
What is the function of oesophagus in digestion?
This is a thin tube that connects the mouth to the stomach.
What is the function of the stomach in digestion?
To mix the food with hydrochloric acid. It mixes it up and churns the food with it’s muscles.
What is the function of Liver in digestion?
It makes a chemical called bile
What does bile do?
- It breaks down lipids.
- neutralise hydrochloric acid from the stomach
- emulsifies fat
What are lipids?
Fats
What is the function of the small intestines
to absorb soluble molecules into the blood stream
What is the function of the large intestines?
to absorb water from undigested foods
What is the function of the Rectum?
to store faeces (undigested food)
What is the function of the anus?
to excrete the faeces
What does the hydrochloric acid do in digestion?
it kills bacteria and provides the optimum pH for the protease enzyme to work
What is the function of digestive enzymes?
to convert food into small soluble molecules which can be absorbed into the bloodstream
What do Carbohydrases do?
break down carbohydrates to simple sugars
What is amylase?
a carbohydrase which breaks down starch
What is the function of proteases?
to break down proteins to amino acids
What is the function of Lipases?
to break down lipids (fats) to glycerol and fatty acids
What is the name of the food test for simple carbohydrates (sugars)?
Benedict’s test
What is the colour change in the Benedict’s test?
from blue to green, orange or Brick red
What does green mean in Benedict’s test?
low levels of sugar
What does Orange mean in Benedict’s test?
moderate levels of sugar
What does brick red mean in Benedict’s test?
High levels of sugar
What is the name of the food test for complex carbohydrates (starch) ?
Iodine test
What is the colour change in the iodine test?
Turns from a orange/brown colour to a blue/black colour
What is the name of the food test for Proteins?
Biuret test
What is the colour change in the biuret test?
From blue to a lilac/purple colour
What is the name of the food test for Fats?
Ethanol and Water test
What is the colour change in the ethanol and water test?
From transparent to a cloudy/milky emulsion
What is the fastest food type to digest
carbohydrates
What happens to excess carbohydrates
They are stored as fats, which can make you gain weight.
what are 2 food examples of simple carbohydrates?
sweets ,biscuits, cake
what are 2 food examples of complex carbohydrates?
Bread, pasta, rice, potatoes
What are 2 food examples of proteins?
chicken, fish, eggs, nuts, beans
What are 2 food examples of fats?
butter, oil, fish, avocado
What are amino acids bonded by?
peptides
what are fats made up of?
triglycerides - one glycerol and 3 fatty acids
What are triglycerides held together by?
ester bonds
what type of bonds are carbohydrates bonded by?
glycosidic bonds
when an enzyme is involved it is called…
chemical digestion
What is an enzyme?
a biological catalyst that breaks down large chain molecules into small chains or individual molecules
what is something that speeds up a chemical reaction called.
a catalyst
True or False
enzymes change/become used up in a reaction
False, enzymes remain the same
what do enzymes break down?
substrates
What is a substrate?
a food molecule
Where does the reaction take place in an enzyme?
active site
how does the substrate enter the enzyme?
using the lock and key model
what is the lock and key model?
the substrate must be complementary to the active site
what are the products that leave the enzyme?
small chains of food molecules
What do enzymes lower?
the activation energy
What happens in digestion as the temperature rises?
the rate of reaction increases
What happens when the temperature reaches the optimum temperature for the enzymes?
the rate of reaction is at it’s peak.
What happens when the temperature goes past the optimum temperature?
the rate of reaction slows down because the enzymes denature
what happens when an enzyme denatures?
It’s active site changes shape meaning no substrate can attach onto it and digest.
What is the collision theory?
That particles must bounce of each other in order to react with each other.
How does the collision theory apply to digestion?
because an enzyme and substrate must meet to form an enzyme- substrate complex to form products.
What happens when the pH is too acidic?
The enzyme cannot work well and the rate of reaction is slower
what happens when the pH is above the optimum pH level for enzyme action?
the enzymes denature and rate of reaction decreases.
What are the small intestines filled with?
villi
What are the cells on the villi?
microvilli
What does having the microvilli do?
increase the total surface area
What does increasing the surface area of villi do?
increase the volume of substances which are absorbed by diffusion
Villi have a very good ____ supply.
blood
what does each villi contain?
a capillary
where does the capillary lead to?
the main blood supply
how does the adaption of the capillary effect the villi?
allows substances to go straight to the bloodstream
what is an adaption the villi have to do with their walls?
they are one cell thick
what does the adaption of the one cell wall thick cell do?
it makes a shorter distance allowing substances to diffuse faster
Where is bile made?
liver
what happens in the gall bladder?
bile is stored
what does bile do in the stomach?
it neutralises the acid, so it becomes more alkaline in the small intestines
why do lipases work best in the small intestines?
because conditions are more alkaline
What does bile do to fat molecules?
emulsified into fat droplets
what do the fat droplets allow?
for a bigger surface area for lipases to break down.
What are carbohydrates used for?
as an energy source in respiration
What are proteins used for?
growth, repair, enzymes, antibodies and hormones
What are lipids used for?
cell membranes, hormones and nervous system
where is protease made?
stomach, pancreas and small intestine
where are lipase made?
pancreas and small intestine
Where is amylase made?
salivary gland and small intestines and pancreas
why do different enzymes have different optimum pH’s?
because they are from different parts of the digestion system
