B3 Flashcards
What are cells?
The building blocks of all living organisms
How do single cells carry out exchanges?
Across their cell membrane
What is a tissue?
A group of cells with similar structure and function working together
What does the muscular tissue do?
Contract and relax to bring about movement.
What does the glandular tissue do?
Contains secretory cells that can produce and release substances such as enzymes and hormones
What does the epilethal tissue do ?
Covers the outside of the body and the internal organs.
What is an organ?
A collection of tissues working together to perform a particular function
What tissues does the stomach organ contain?
- muscular tissue- to churn the food and digestive juices of the stomach together
- glandular tissue- to produce digestive juices that break down food
- epithelial tissue- which covers the inside and the outside of the organ
Which organ has tissues that are completely different?
The pancreas , two different tissue that produce enzymes that digest food and also hormones . Two completely different tissues
What is an organ system?
A whole multicellular organism made up of a group of organs that work together to perform a specific function.
Examples of organ system?
Digestive system
Circulatory system
Gas exchange system
What does a group of organ systems create?
Organism
What is the digestive system?
A organ system in which several organs work together to digets and absorb food.
What does the mouth, salivary glands and oesophagus do?
Mouth is where food enters, salivary glands produce saliva that contain amylase enzymes. The oesophagus is the tube that the food is squeezed down
What does the pancreas do in the digestive process?
Produce enzymes and release them in the stomach
What does the liver do?
Produces bile , releases into the stomach.
What does the gall bladder do ?.
Store bile , before releasing it
What does the small intestine do ?
Duodenum is where the food is mixed with bile and digestive enzymes
Then food moves to ileum where digested food is absorbed into blood and lymph , to go to necessary cells
What happens in the large intestine?
Colon is where water is reabsorbed
Rectum is where faeces is stored
Anus is where faeces leaves alimentary canal
Process of digestion?
- Mouth
- Salivary glands
- Oesophagus
- Pancreas
- liver
- Gall bladder
- Small intestine
- Large intestine
What do glands do?
Produce digestive juices containing enzymes
Where does digestion take place?
Stomach and small intestine
What do enzymes do ?
Break down insoluble food molecules into smaller soluble ones
How is the small intestine adapted?
- large surface area, covered in villi
- good blood supply
- short diffusion distances.
What are the main compounds that make up the structure of the cell and are vital for a balanced diet?
- carbohydrates
- lipids
- proteins
Why carbohydrates are important?
Provide us with fuel to make all other reactions possible
What elements do carbohydrates contain?
Carbon
Hydrogen
Oxygen
What makes up carbohydrates?
Sugar units
What is the carbohydrate made up of only one sugar molecule?
Simple sugar, eg glucose C6H12O6 or sucrose
What are complex carbs?
Carbs with long chains of sugar molecules.
Examples of complex carbs?
Starch , cellulose
Examples of carb rich food?
Bread
Potatoes
Pasta
What happens to most carbohydrates when taken into the body?
Broken down into glucose and used for cellular respiration to provide energy for metabolic reactions.
What does carbs do for the plants?
Cellulose is a support material in plants
Examples of lipids?
Fats and oils
What are lipids?
Energy efficient store in the body and important energy source for your diet
Why lipids are important?
Combined with other molecules, lipids are important in the cell membrane , as hormones and in the nervous system
Are lipids soluble in water?
No
What elements are in lipids?
Carbon
Hydrogen
Oxygen
What makes up lipids?
3 molecules of fatty acid, joined with a molecule of glycerol. Glycerol is always the same but fatty acids can differ.
Examples of lipids?
Oil, margarine , cheese, butter
What are proteins?
Basic building block of all tissues in the body
Basis of enzymes
What elements make up proteins?
Carbon , hydrogen , oxygen, nitrogen
What makes up proteins?
Long chains of small units of amino acids
How many amino acids are there ?
Around 20
What makes different proteins?
Different arrangements of amino acids. They are twisted, folded and coiled to make specific 3d shapes
How strong are bonds between amino acids?
Sensitive to ph and temperature
What happens if proteins loses its function?
Becomes denatured
What functions do proteins carry out?
- structural components of tissues such as muscle and tendons
- hormones such as insulin
- antibodies , part of immune system , destroy pathogens
- enzymes which act as catalysts
What is a catalyst?
Speeds up chemical reactions , but is not used up in it. Can be used over and over again
What controls the rate of chemical reactions?
Controlled by enzymes
What do enzymes interact with?
Substrate
What is the active site of an enzyme?
A section on an enzyme that can bind to a particular substrate. It is vital otherwise enzyme wont work
What is bile?
Made in the liver and stored in the gall bladder. Its alkaline to neutralise hydrochloric acid from the stomach . It also emulsifies fats to form small droplets which increases the surface area. The alkaline conditions and large surface area increase the rate of fat breakdown by lipase
What is the lock and key theory?
Enzymes have a specific active site to the substrate. This active site and the substrate binds to speed up the reaction of the substrate to create products.
What enzyme breaks down protein?
Protease
What happens when protein breaks down protease?
Breaks it down into individual amino acids and they are absorbed into the blood stream
What happens when amino acids are absorbed by body cells?
Joined together in a different order to make human proteins
What enzyme breaks down starch ?
Amylase
What produces protease?
Pancreas, stomach and small intestine
What breaks down lipids?
Lipase
Where is amylase produced?
Salivary glands , pancreas
Where is lipase produced?
Pancreas and small intestine
What breaks down simple sugars?
Carbohydrases
What is an enzyme?
A biological catalyst
What controls the rate of reaction.
Enzymes
What makes up enzymes?
Large protein molceules
How is an enzymes active site formed?
Long chains are folded to produce a molecule with an active site , that can bind to a specific substrate.
What is the lock and key theory?
- substrate fits into active site.
- bind together and the reaction takes place rapidly and the products released from the surface of the enzymes
- enzymes can also join small molecules together
What do enzymes control?
Metabolism
What is the metabolism ?
Sum of all chemical reactions in the body.
Why do enzymes break down molecules ?
- glucose for cellular respiration(absorbed into blood stream)
- amino acids to form urea.
Why the shape of the active site is important?
Enzymes are specific to the substrate . Must fit perfectly or doesn’t work
How does temperature affect the activity of enzymes?
- increase temperature , activity increases. Enzymes and substrate moving faster.
- one hit optimum temperature , it is working at its maximum .
- once going past optimum temperature the activity of the enzyme rapidly decreases to 0
What happens once the temperature of enzymes exceeds the optimum temperature ?
Vibrate rapidly and the active site changes. The substrate can no longer fit into the active site , so it is denatured.
How does ph affect enzyme activity ?
Enzymes have an optimum ph . If ph becomes more acidic or alkali , the enzyme activity drops to 0. Each enzyme has a specific optimum ph
How small intestine is adapted to be efficient?
- very large surface area for absorption of the products of digestion
- interior covered in villi to increase surface area
- microvilli increase it even more
- villi have a good blood supply so blood stream rapidly removes products of digestion
- villi have a thin membrane , short diffusion path
- molecules not absorbed by diffusion ,are by active transport.
