Chapter 3 B3 Pages 36-51 Flashcards
What is a tissue?
A tissue is a group of cells with similar structure and function working together.
What is an organ?
Organs are collections of tissues. Each organ contains several tissues, all working together to perform a specific function. For example, the stomach is an organ involved in the digestion of food.
What is an organ system?
A whole multicellular organism is made up of a number of organ systems working together. Organ systems are groups of organs that all work together To perform specific functions. The way in which one organ functions often depends on other organ system.
Describe the function of the small intestine
Absorption of soluble substances
Describe the function of the liver
Production of bile
Describe the function of the pancreas
Secretion of digestive enzymes
Describe the function of the stomach
Site of some protein digestion
Describe the structure and function of the mouth
Chew increase surface area to enzyme amylase to starch
Describe the structure and function of the salivary glands
Enzyme called amylase catalyses reaction breaking down starch into simple sugars. Also contains mucus making the food easier to eat.
Describe the structure and function of the gullet (oesophagus)
Has muscles in its wall. These muscles contract behind the food to push it along towards the stomach. This wave-like contraction is called peristalsis.
Describe the structure and function of the stomach
Food is mixed with stomach acid the protein-digest enzymes work quickly. Stomach acid also kills bacteria.
Describe the structure and function of the pancreas
Control glucose in the blood. Glucose levels tend to rise when eating causing insulin to be released causing excess glucose to convert to glycogen for storage in liver. When blood sugar drops, insulin secretion is replaced by glucagon which converts glucagon back to glucose.
Describe the structure and function of the rectum
Semi-solid material (feces) collects in the rectum before leaving the body through the anus.
Describe the structure and function of the liver
Produces a liquid called bile stored in the gall bladder, bile travels through bile duct into the small intestine. The bile breaks up fat.
Describe the structure and function of the large intestine
Absorbs water into the blood, undigested food becomes more solid.
Describe the function of the pancreas
Organ that makes and releases digestive juices containing enzymes to break down your food.
Describe the function of the stomach
Organ where food is churned with digestive juices and acids
Describe the function of the small intestine
Organ where small digested molecules are absorbed into the bloodstream.
Describe the function of the large intestine
Organ where water passes back into the body, leaving solid waste.
What are protein’s uses?
Act as hormones
Act as antibodies
Act as enzymes
Structural components such as muscle
What are carbohydrate’s uses?
Broken down and used in cellular respiration
Support material in plants
What are fats and oils uses?
Insulation
Efficient energy store
What are carbohydrates?
Carbohydrates provides us with the fuel that makes all the other reactions in life possible. They contain the chemical elements carbon, and oxygen.
What are all carbohydrates made up of ?
All carbohydrates are made up of units of sugars.
What do some carbohydrates contain give an example?
Some carbohydrates contain only one sugar unit. The best known of these single is glucose, C H12 O6 .
What are other carbohydrates made up of?
Other carbohydrates are made up of two sugar units joined together, e.g. sucrose, the compound we call,’Sugar,’ in everyday life. These small carbohydrate units are referred to as simple sugars.
What are complex carbohydrates made up of?
Complex carbohydrates such as starch and cellulose are made up of long chains of simple sugar units bonded together.
Give some examples of carbohydrate rich foods.
Carbohydrate rich foods include bread, potatoes, rice and pasta.
What are most of the carbohydrates we eat broken into?
Most of the carbohydrates we eat are broken down into glucose which is used in cellular respiration to provide energy fro metabolic reactions in your cells. The carbohydrate cellulose is an important support material in plants.
What are lipids?
Lipids are fats (solids) and oils (liquids). They are the most efficient energy store in your body and an important source of energy in your diet.
Why are lipids very important?
Combined with other molecules, lipids are very important in your cell membranes, as hormones, and in your nervous system.
What are lipids made up of?
Like carbohydrates, lipids are made up of carbon, hydrogen and oxygen. All lipids are soluble in water.
How man molecules and of what type are lipids made up of?
Lipids are made up of three molecules of fatty acids joined to a molecule of glycerol. The glycerol is always the same, but the fatty acids are different.
What are lipid-rich foods?
Lipid-rich food includes all the oils, e.g. olive oil and corn oil, as well as butter, margarine, cheese and cream (dairy).
What affects the lipid to be liquid or solid?
The different combination of fatty acids affects whether the lipid wil be a liquid oil or a solid fat.
What are proteins used for?
Proteins are used for building up the cells and tissues of your body, as well as the basis of all your enzymes.
How much of your body mass is made up of protein?
Between 15 and 16% of your body mass is made up of protein.
Where is protein found?
Protein is found in tissues ranging from your hair and nails to the muscles that move you around and the enzymes that control your body and how it works.
What are proteins made up of?
Proteins are made up of the elements carbon, hydrogen, oxygen and nitrogen. Protein-rich foods include meat, fish, pulses and cheese. A protein molecule is made up of long chains of small units called amino acids.
what is the hierarchy of living organisms
Hierarchy of living organisms: cells to tissues to organs to organ systems to organisms
state 3 food nutrients
carbohydrate
proteins
fats
describe the food nutrient carbohydrate
Carbohydrate: composed of long chains of simple sugars e.g. glucose molecules
describe the food nutrient protein
Proteins: composed of chains of amino acids
describe the food nutrient fats
Fats: composed of 3 fatty acids & 1 glycerol molecule
what do proteins act as
act as hormones
act as antibodies
act as enzymes
acts as structural components such as muscle
what are carbohydrates uses
broken down and used in cellular respiration
support material in plants
what are fats and oils uses
insulation
efficient energy store
what is the food test for starch
1 Place a small amount of food on the spotting tile.
2 Add a few drops of iodine solution to the food on the spotting tile.
3 Yellow–red iodine solution turns blue–black if starch is present.
4 Repeat steps 1–3 for other types of food.
5 Record all your results in a results table.
what is the food test fo sugar
1 Place a small amount of food in a test tube.
2 Add enough Benedict’s solution to cover the food.
3 Place the test tube in a warm water bath for 10 minutes.
4 Blue Benedict’s solution turns brick red on heating if a sugar such as glucose is present.
5 Repeat steps 1–4 for other types of food.
6 Record all your results in a results table.
what is the food test for lipids (fats)
1 Place a small amount of food into a test tube.
2 Add a few drops of ethanol to the test tube.
3 Shake the test tube and leave for one minute.
4 Pour the solution into a test tube of water.
5 Ethanol added to a solution gives a cloudy white layer if a lipid is present.
6 Repeat steps 1–5 for other types of food.
7 Record all your results in a results table.
what is the food test for protein
1 Place a small amount of food in a test tube.
2 Add 1 cm3 of Biuret reagent. Alternatively, add 1 cm3 of sodium hydroxide
solution and then add a few drops of copper sulfate solution.
3 Blue Biuret reagent turns purple if protein is present.
4 Repeat steps 1–3 for other types of food.
5 Record all your results in a results table.
What is an enzyme?
An enzyme is a biological catalyst that speeds up the rate of chemical reactions in the body. Enzyme activity is affected by changes in temperature and pH.
Explain how enzymes work
- Enzymes are proteins. They speed up the rate of chemical reactions.
- They have a specific shape called the active site
- The active site is complementary to the shape of the substrate molecule. Like a lock and
ke - There are random collisions between the enzyme and the substrate molecule, when the
substrate enters the active site an enzyme substrate complex is formed. - Bonds are broken
- Produce are released.
- Enzyme can then be reused.
what do enzymes require
Enzymes require an optimum pH and temperature as they are proteins.
what is the best temperature for enzymes
the optimum (best) temperature for enzymes is 37C (body temperature).
what happens when increase the temperatures of the enzyme
Increasing temperatures: both the enzyme and substrate molecules have more kinetic energy, therefore there are more frequent collisions, more enzyme substrate complexes are formed and more products are released.
what happens to the enzymes above 40 degrees celsius
Over 40°C the bonds in the enzyme start to break, therefore the enzyme starts to become denatured and no longer functions. The substrate can no longer fit into the active site.
how does pH affect the enzyme
each enzyme has an optimum pH. They only work within a narrow range of pH. Higher/lower pHs cause the enzyme to become denatured.
name three types of enzymes
protease
lipase
carbohydrase for example amylase
where are protease found
the production site of protease are in the stomach
the pancreas and
the small intestine
where are lipase found
the production site of lipase are in the pancreas and
the small intestine
where are carbohydrase found
the production site of carbohydrase are in the salivary glands
the pancreas and
the small intestine
where do the protease work
in the stomach and in the small intestine
where do the lipase work
in the small intestine
where do the carbohydrase work
in the mouth and the small intestine
what are digestive enzymes
There are many different type of enzymes that speed up reactions in different parts of the digestive system. You need to know where these enzymes are made and where they function. See table below.
what is bile
Bile: a green alkaline liquid produced by the liver and stored in the gallbladder. It neutralises stomach acid and emulsifies fats (which gives a larger surface area for the enzyme lipase to act).
Where is food absorbed into the bloodstream
the small intestine
Where is water reabsorbed back into the bloodstream
the large intestine
what is the method to find out factors affecting enzymes
Method
1 Use the syringe to place 2 cm3 of amylase solution into a test tube.
2 Use another syringe to add 1 cm3 of pH buffer solution to the test tube.
3 Place the test tube into a water bath set at 30 C and leave for 5 minutes.
4 Whilst waiting, add a drop of iodine solution into each dimple of a spotting tile.
5 After 5 minutes, use another syringe to add 2 cm3 of starch to the amylase/buffer solution, start the stop clock and leave it on throughout the test. Mix using a plastic pipette.
6 Remove a drop of amylase/starch/buffer mixture after 30 seconds and add to the first drop of iodine on your spotting tile.
7 Wait another 30 seconds. Then remove a second drop of the mixture to add to the next drop of iodine.
8 Repeat step 6 until the iodine solution and the amylase/buffer/starch mixture remains orange.
9 Record the time taken for the amylase to fully digest the starch.
10 Repeat the whole procedure with a different pH buffer.
