Enzymes and Digestion Flashcards
what is the order of level of organisation from smallest to largest?
cell, tissue, organ, organ system,organism
what are tissues?
A group of similar cells carrying out the same function
what are cells?
The simplest, basic unit of life where all chemical processes takes place
what is an organ system?
Made up of many organs that work together as one system
what is an organ?
Made up of more than one type of tissue grouped together to perform a task
a group of cells make a….
tissue
a group of tissues make a…
organ
a group of organs make a….
system
a group of systems makes a….
organism
what are the types of tissue?
Epithelial tissue, Muscular tissue, Glandular tissue
what does epitherial tissue do?
Epithelial tissue covers and lines all organs.
what does muscular tissue do?
Muscular tissue contracts to bring about
movement
what does glandular tissue do?
Glandular tissue produces
secretions e.g. mucus
what do each of the tissues in the stomach do?
Muscular tissue, to “churn up” the contents (mastication)
Glandular tissue, to produce digestive juices
Epithelial tissue, to cover the outside and inside of the stomach
how does digestion work?
Glands such as the salivary gland and the pancreas produce digestive juices
Digestion occurs in the stomach and small intestine
Bile is produced by the liver and helps break down fats
Food is absorbed in the small intestine
Water is absorbed in the large intestine, leaving behind the faeces
what are the stages of digestion?
Physical digestion (mastication)
Chemical digestion (involves enzymes)
Absorption
Assimilation
what is the role of digestion
Digestion is to make sure that large, insolouble molecules are broken down into smaller, soluble molecules that can be absorbed into the blood stream.
what are the main organs in the digestive system?
mouth, stomach, small intestine & large intestine
what are the accesory organs in digestion?
salivary glands, liver and pancreas
why is mastication necessary?
so that your body is prepared to swallow
what is the action of amylase?
breaks down starch into glucose
what is the enzyme responsible for digesting starch?
amylase
what takes place in the oesophegous?
Peristalsis (rhythmic, alternate muscle contractions) pushes the food in one direction
are new enzymes secreted in the oesophagus?
no
what does the stomach secrete?
gastric juice
what is the pH pf gastric juice and how is the acid provided?
pH of 2 provided by Hydrochloric acid
what is the enzyme responsible for digesting protien?
PROTEASE
where is amylase produced in?
salivary glands, pancreas and small intestine
where is protease produced in?
Proteases are produced in the stomach (pH 2) and the small intestine (pH 8) and pancreas
what is the action of protease?
breaks down PROTEIN to AMINO ACIDS
where is bile produced?
liver and it stored in the gall blader.
what are biles functions?
It neutralises stomach acid and produces alkaline conditions for enzymes to work in It emulsifies (“breaks down”) fats to increase the surface area:
what do lipids do to increase sufrace area and increase the rate of digestion?
get emulsified by bile
what substrate is amylase
starch
what substrate is protease
protien
what substrate is lipase
lipids
what is the product of amylase
GLUCOSE
MALTOSE
what is the product of protease
AMINO ACIDS
what is the product of lipase
FATTY ACIDS
where is lipase produced in?
Pancreas/
Small Intestine
what is the optimum pH for amylase
8
what is the optimum pH for protease
8 and 2.5 (stomach)
what is the optimum pH for lipase
8
The small intestine is the only organ in which both ……… and ……… take place
The small intestine is the only organ in which both digestion and absorption take place
digestion of all food group occors in the
small intestine
where does the small intestine recieve bile from
the liver
where does the small intestine recive pancreatic juice from?
the pancrease
what features of villi and microvilli speed up the rate of reaction?
A large surface area – provided by millions of villi to increase the rate of diffusion
A very thin membrane – just one layer of cells to shorten the distance for diffusion
A rich blood supply – the flow of blood helps to maintain a steep concentration gradient for diffusion
what does the large intestine consit of?
colon, rectum and anus
where does absorbtion of water in the large intestne take place and why?
in the colon to make the faeces dry
when does the urge to go to the toilet develop?
when the rectum is full of feaces
where is feases expelled through?
the anus
what are the factors that effect enzyme activity?
Temperature
pH
Concentration/Volume of either enzyme or substrate
enzymes are sensitive to temperature describe the graph with shows this.
Between 0 – 40 as the temp increases the rate of reaction increases in a linear relationship
Beyond 40, as the temp increases the rate of reaction decreases and stops at 50 C
40 is the optimum temp
as the temp increases heat energy is converted into?
kinetic energy
what happens to the enzyme and substrate when the temperatre increases?
enzyme and substrate collide more and more product forms
what happens to enzymes when the temp is too high
he enzyme denatures and the active site changes shape so that the substrate no longer binds
what do the enzyme and substrate do with more energy?
they move
enzymes are sensitive to temperature explain the graph with shows this.
Between 0 – 37
As temp increases the particles gain kinetic energy which increases the number of collisions between enzyme & substrate
Between 40 – 60
As the temp exceeds the optimum, the enzyme denatures and the active site changes shape so the substrate no longer binds. The enzyme has denatured.
what is the optimium pH for enzymes?
7
explain the enzyme pH graph?
The optimum pH is 7. On either side of the optimum the enzyme activity decreases uniformly. This is because the enzyme denatures due to change in shape of the active site so the substrate can no longer bind
explain the enzyme concentration graph
Enzymes will work best if there is plenty of substrate. As the concentration of the substrate increases, so does the rate of enzyme activity. However, the rate of enzyme activity does not increase forever. This is because a point will be reached when the enzymes become saturated and no more substrates can fit at any one time even though there is plenty of substrate available.
in the required practical ‘food tests’ how do you test for glucose?
1) take 5 ml of glucose solution into a clean test tube
2) add 10 drops of Benedicts soloution to the glucose solution in the test tube.
3) put the test tube in an electronic water bath fpr 5 mins
4) note any color change
in the required practical ‘food tests’ how do you test for starch?
add a few drops of starch soloution to a spotting tile. next add a few drops of idone soloution to the starch and note any color change.
in the required practical ‘food tests’ how do you test for lipids?
take some oil into a clean test tube and add a few drops of ethanol and shake until it dissolves. pour the mixture into a test tube of water and note what coulor you see?
in the required practical ‘food tests’ how do you test for protein?
put 2cm3 of protien soloution intoa test tube. add 2cm3 of biuret soloution in the test tube. shake gently to mix. note any color change.
what colour will a soloution go if glucose is present?
blue to orange to red
what colour will a soloution go if starch is present?
brown to blueblack
what colour will a soloution go if lipids is present?
cloudy white emulsion
what colour will a soloution go if protien is present?
blue to purple
how do you investigate the effect of pH on the enzyme amylase?
Place one drop of iodine solution into each depression on the spotting tile
Place labelled test tubes containing the buffered pH Solutions amylase solution and starch solution into the water bath
solutions to reach 25 degrees
add 2 cm cubed of one of the buffered solutions to a test tube
use the syringe to place to 2 centimetres cubed of amylase into the buffered pH solution
use another syringe 2 add 2 cm cubed of starch to the amylase buffer solution
immediately start stop clock and leave it on through the test
mix using a glass rod
after 30 seconds remove one drop of the mixture with a glass rod places drop on the first depression of the spotting tile with the iodine solution solution should turn blue black
Rinse the rod
use the glass rod to remove one drop of mixture every 30 seconds each drop onto the iodine solution in the next depression spotting tile rod with water after each drop continue until the iodine solution of amylase / buffer/starch mixture remain Orange
repeat the procedure with Solutions of other PHS
record your results in a results table
