Part A Flashcards
What are the three structures found in plants but not in animal cells?
Vavuole
Chloroplasts
Cell wall
What is the structure that makes proteins?
Ribosimes
What holds the genetic information in a cell?
The nucleus
What controls the movement between cells?
The cell membrane
Where do the chemical reactions in a cell?
Cytoplasm
Where is the cell sap kept in the cell?
In the vacuole
What is the structure of a bacteria cell?
Bacteria are single-celled organisms. Their genetic materials is not contained with a nucleus. Some cause disease, but many are useful.
What is the structure of a fungi cell?
Complex structure of all microbes. They feed of other living organisms.
What does a bacterial cell not have?
A nucleus
What is diffusion?
The movement of a substance from an area of high concentration to an area of low concentration
Give an example of diffusion
On one side there is cotton wool dipped in hydrochloric acid and the other is cotton wool dipped in ammonia. When the particles meet via diffusion they make a new substance called ammonium chloride. Ammonia is a lighter/smaller molecule so diffuses quicker than hydrochloric acid. This is why they do not meet at the middle.
What are the three factors that increase the rate of diffusion ?
- By increasing the surface area-more space to diffuse across
- Decreasing the diffusion distance
- Greater concentration difference (gradient)
What is a tissue?
A tissue is a group of specialised cells that have a similiar structure and function
What are the three types of tissue?
Muscular- relax and contract to move our skeleton
Glanduar- produce secretion
Epithelial- coverig our body-organs
How are organisms cells and organs adapted to maximise the rate of diffuse?
The membrane is selectively permeable, and they have a large surface area
Explain why diffusion takes place faster when there is an increase in temperature
There is more kinetic energy as you have added more heat
Explain in terms of diffusion why so many cells have folded membranes along at least one surface
A folded membrane has increased the surface area which speeds up the rate of diffusion
What is the specialised plant cell that carries water?
The xylem
What are the organelles where the reactions of respiration take place?
Mitochondria
What is absorbed in the small intestine?
This is where the absorption of the food molecules in the blood stream takes place
What does the liver produce?
This organ produces bile which is used to break down large fat globules into smaller droplets
What does the stomach contain?
This organ contains protease, enzymes and also hydrochloric acid to kill bacteria
What does the salivary gland produce?
It produces saliva which contains the enzyme carbohydrase
What does the pancreas produce?
It produces carbohydrase, lipase and protease enzymes and releases them to the small intestine
What is stored in the rectum?
Faeces
What happens in the mouth?
Food is chewed up by the teeth here and swallowed
What is the oesophagus?
A tube that connect the mouth to the stomach
What leaves the anus?
Faeces
What is absorbed in the large intestines?
Water from the waste food is absorbed here
What does the gall bladder store?
This organ stores bile
What does bile do?
Bile helps with the digestion of fat/lipids made in the liver and stored in the gall bladder
What is an enzyme?
A folded protein molecule
Fold produce a unique shape
Shape of enzyme determines what the enzyme can react with
What happens if you increase the temperature of an enzyme?
The rate of reaction will increase, however if you add too much heat it will denature the enzyme
Why are only small amounts of enzyme are needed?
You can re-use an enzyme
Where is lipase made?
Pancreatic juices and intestinal juices
Where does lipase work?
In the small intestine
What does lipase do?
Turns fats into fatty acids and glycerol by breaking it down
Why do we have acid in the stomach?
To break down food- enzymes that work in the stomach are specific this is the optimum conditions
What is the function of bile?
It is an alkali and neutralises acid which was added to the food in the stomach. In addition, bile emulsifies fats- increases the surface area of fats for lipase enzymes to act upon
Where is amylase made?
In the mouth, pancreas and small intestine
Where does amylase work?
In the mouth and small intestine
What does the amylase do?
Digest starch to sugar
What is protease made?
Pancreas juices, intestinal juices and stomach
Where does the protease work?
Stomach and small intestine
What does the protease do?
Turns proteins into amino acids by breaking them down
Why do we need to digest food?
So we can absorb the nutrition into our body and can excrete the food we consume. Small molecules are absorbed into the blood
Name some uses of enzyme in industry
Carbohydrase are used to convert starch into sugar
Protease are used in baby food and washing powder as it helps break down the protein
Lactase is used to produce lactose free milk as it breakdowns lactose into glucose and galalose
What are the advantages of using enzymes in industry?
It lowers the temperatures and pressures required for reactions. Means cheaper equipment can be used
Lower energy costs
What are the disadvantages to using enzymes in industry?
They can be expensive to produce
Can be hard to extract from the product (unless immobilised)
Need to keep conditions constant to not denature enzyme
Why do we need energy?
To move
To make amino acids or proteins
What is the word equation for aerobic respiration?
glucose + oxygen ——-> carbon dioxide + water + energy
Where does most of respiration reactions take place?
In the mitochondria
What cells need more mitochondria?
Muscle cells have more mitochondria as they require more energy
What is the word equation for anaerobic respiration?
Glucose —> lactic acid + energy
What are the differences between aerobic and anaerobic respiration?
Anaerobic does not require oxygen and produces lactic acid, however makes less energy than aerobic
Aerobic requires oxygen but has more energy
What is meiosis?
A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores
What is a gamete?
Another term for sex cells
What is mitosis used for?
Used for growth and repair of cells
Used in sexual reproduction
What is produced out of mitosis?
Cells with identical number of chromosones and genetic information are produced
What is meiosis used for?
Used to produce gametes for sexual reproduction
