Chapter B3 Organisation And The Digestive System Flashcards
What is a tissue?
A group of cells with similar structure and function working together
What is an example of human body tissue?
Epithelial tissue- covers outside of your body and your organs
Glandular tissue- contains secretory cells that can release and produce substances such as hormones and enzymes
What is an organ?
A collection of tissues, working together to form a specific function
Give an example of an organ?
Stomach
Pancreas
What is an organ system?
A group of organs working together to perform a specific function
Name an organ system in the human body
Digestive system
Circulatory system
Gas exchange system
What is an organism made up of?
A multicellular organism is made from groups of organ systems
What are the main organs where food is digested?
Stomach and small intestine
What are carbohydrates broken down by?
Carboghydrases like amylase
Where is amylase found?
The salivary glands and the pancreatic fluid
What is a lipid molecule?
Consists of glycerol attaches to three molecules of fatty acid
What is a lipid digested by?
Liphase
What helps to speed up the digestion of lipids?
Bile- it is an alkaline which allowes it to neutralise the stomach acid, creating alkaline in the small intestine
Where is bile stored and made?
Gall bladder
Why do humans have a digestive system?
To break our food molecules down so that it can be absorbed
What are proteins broken down by?
Proteases such as pepsin
What are carbohydrates made up of and what is an example of a carbohydrate?
Carbohydrates are made up of simple sugars
Example is bread, potatoes, pasta and rice
What are lipids made up of and give an example of a lipid?
Lipids are made up of glycerol and three molecules of fatty acids
Example is rich food such as olive oil, butter, margarine and cheese.
What are proteins made up of and what is an example of a protein?
Proteins are made up of amino acids
An example is chicken or fish
What do carbohydrates do?
Provide us with sustainable energy that is long lasting
What do lipids do?
Source of energy and an important energy store- important for cell membranes and nervous system
What do proteins do?
Used to build up cells and tissues of your body, and are also the basis of your enzymes.
They act as antibodies, hormones like insulin, and enzymes
Basic process of digestion for lipids?
Mouth - teeth chew
Tongue- rolls food into a ball
Oesophagus- pushes food to stomach by peristalsis
Stomach- produces HCL which kills bacteria on food and creates acidic environment for enzymes to work
Small intestine- liquid bile is produced which emulsifies the fat. This neutralises the stomach acid. Pancreatic lipase are also present.
Large intestine- excess water is removed and taken to blood stream
Anus- undigested food exits by excretion
What does emulsifies mean?
Breaks up the fat into smaller droplets
Basic process of digestion of carbohydrates?
Mouth- salivary glands produce amylase- turns starch into maltose. Teeth grind the food.
Tongue- rolls into ball
Oesophagus- pushes food to stomach by peristalsis
Stomach- kills bacteria on food and creates acidic environment
Small intestine- pancreatic amylase breaks remaining starch to maltose. Enzymes then turn this into glucose. Intestinal walls also produce maltase, which turns maltose to glucose.
Large intestine- excess water is removed. Remaining starch is excreted.
How does the body prevent constipation?
Takes the water from the undigested food
Basic process of digestion of proteins?
Mouth- teeth chew food
Tongue- rolls into ball
Oesophagus m- pushes to stomach by peristalsis
Stomach- proteases are released, kills bacteria on food and creates acidic environment
Small intestine- releases protease that breaks down the proteins into amino acids
Large intestine- excess water is removed and excreted through the anus
What is a catalyst?
Speeds up chemical reactions
What do enzymes react with?
A substrate
What is an enzyme?
A large protein molecule
The long chains of amino acids are folded to have unique shapes- why?
To produce a molecule that can bond to the active site of a specific substrate
What is the lock and key theory?
The substrate of the reaction fits with an enzyme so it can be catalysed, like a lock and key
Explain what an enzyme does
Joins with a substrate which fits into its specific active site
Then binds to create an enzyme substrate complex
The substrate then splits into new products and the enzyme is ready to use again
Do enzymes change a reaction?
No they just make it faster
What do enzymes control?
Metabolism
Give examples of metabolic reactions
Building large molecules from various smaller ones- building starch from glucose
Breaking large molecules into smaller ones- breaking down carbohydrates
Changing one molecule into another- changing sugars like glucose to an amino acid
What factors effect enzymes?
Temperature and PH level
How does temperature effect an enzyme?
The activity of the enzyme initially increases, until its optimum is reached. When an enzymes optimum is reached, the enzyme becomes denatured and stops working.
For human enzymes this is 41 degrees. Their optimum is 37 degrees
What is the effect of PH on an enzyme?
Can change he shape of the molecule, resulting in the specific active site being lost, and thus the enzyme no longer being able to act as a catalyst. Each enzyme has an optimal PH, such as lipase working best at an alkaline PH
What does mucus protect in the stomach during digestion?
Protects stomach walls from acid and protects them from being digested by the enzymes and acid
If someone develops a muscle ulcer, why may they be in pain?
The lining of the stomach is attacked by the acid and protein eating enzymes
Give an example of how your body changes PH level?
Bile neutralises the stomach acid so that the small intestine conditions are alkaline
How does your body alter the surface area to aid digestion?
The bile also emulsifies the lipids, resulting in a larger surface area of fats for the lipase enzymes to act upon
