Nat 4 - Cell Biology Flashcards
What is the function of a gene?
To code for proteins
Why must daughter cells be exactly the same as the parent cell?
So that no genetic information is lost and the cell can function properly
Where is DNA found?
In the nucleus
How much genes are passed on from each parent?
50% from mother and 50% from father
What are the 3 special properties of an enzyme?
- They speed up chemical reactions
- They remain the same after a reaction
- They are specific
Why is cell division essential?
To allow organisms to grow and repair broken/damaged parts
What is the function of the nucleus?
Controls cell activities
What is the function of chloroplast?
Absorbs suns energy. Site of photosynthesis.
What is the function of the vacuole?
Contains cell sap
What is the function of cytoplasm?
Where all chemical reactions take place
What is the function of the cell wall?
Structural support
What is the function of the cell membrane?
Controls what passes in and out of the cell
What is an enzyme?
A special protein made by living cells and is known as a biological catalyst
What is a substrate?
Molecule that the enzyme works on
What is a product?
Molecule that results from enzyme action
Which cell parts are in both plant and animal cells?
- Nucleus
- Cytoplasm
- Cell Membrane
What is the first stage of mitosis?
Chromosomes appear in the nucleus
What is the second stage of mitosis?
Chromosomes shorten and appear as double threads joined at one point
What is the third stage of mitosis?
The membrane around the nucleus disappears and chromosomes line up
What is the fourth stage of mitosis?
Chromatids are pulled apart and move to opposite ends of cell
What is the fifth stage of mitosis?
Nucleus membrane reforms round each group of chromatids. Cytoplasm divides.
What is the sixth stage of mitosis?
The two new cells now go through a period of growth before mitosis starts again in each cell
How many stages are there in mitosis?
Six
What can happen if cell division is uncontrolled?
This can cause cancer
If a cell divides every 20 minutes, how many cells will be produced after 2 hours?
64 cells (see table in summary notes)
What do aseptic techniques do?
They keep conditions sterile and free from unwanted living organisms
What does DNA stand for?
Deoxyribonucleic Acid
Why is DNA a good thing to use to help solve crimes?
Because everybody’s DNA is unique
What is therapeutic cell use?
When we use cells to treat and cure disease. It’s an application of biology.
What is Genetic Engineering? What types of products are made?
Genetic engineering is the process of altering an organisms DNA. It removes DNA from one organism and inserts it into another.
The types of products made are Human insulin, Human growth hormone and factor VIII
What is Stem Cell technology? What types of products are made?
Stem cells are animal cells that have not been specialised yet, and can be found in embryos as embryonic stem cells. They can potentially become any cell type found in an animal body. Embryonic stem cells must be extracted from human embryos.
The types of products made are Bone marrow transplants, Skin grafts, and Cornea repair
What is a degradation reaction?
When an enzyme breaks down a large molecule into smaller molecules
What is a synthesis reaction?
When large molecules are built up from smaller molecules
What makes enzymes specific?
Their shape. They only work on one substrate.
What is the substrate and the product for the enzyme Amylase?
Substrate - Starch
Product - Maltose
(Degradation Reaction)
What is the substrate and the product for the enzyme Catalase?
Substrate - Hydrogen Peroxide
Product - Carbon Dioxide and water
(Degradation Reaction)
What is the substrate and the product for the enzyme Phosphorylase?
Substrate - Glucose
Product - Starch
(Synthesis Reaction)
What 2 industries are enzymes very useful in?
Detergent and dairy industries
What is an advantage of biological detergents?
Reduce fuel costs as less energy is required to heat the water in the washing machine
What is a disadvantage of biological detergents?
Can cause allergic reactions
What enzyme can be added to milk to make cheese?
Rennet
What 3 things do microbes include?
- Yeast
- Bacteria
- Fungi
What are 3 properties of microbes?
- Rapid growth
- Diverse food sources
- Can be used to make a wide range of products
What 2 things can yeast be used to make?
Beer and bread
What 3 things can bacteria be used to make?
Yoghurt, cheese and biofuel
What is photosynthesis?
The process in which green plants are capable of making their own food (sugar) using energy from sunlight
What 5 things to plants require in order to photosynthesise?
- Water
- Light
- Carbon Dioxide
- Chlorophyll
- Suitable Temperature
What are 3 factors that may limit photosynthesis?
- Light intensity
- Carbon dioxide concentration
- Temperature
What is respiration?
The process that all living cells use to release the energy from the food that they consume
What 2 factors affect respiration?
Temperature and pH
How much energy is produced in Anaerobic Respiration? What products are made in animals/plants?
Little.
Animals - lactic acid
Plants - ethanol
How much energy is produced in Aerobic Respiration? What products are made in animals/plants?
Lots.
Animals - CO2
Plants - Water
What can photosynthesis be measured by?
- Counting the number of oxygen bubbles produced
2. Weighing the increase in dry mass of the plant
Explain why fermentation is reversible in animals but irreversible in plants
In plants, gas is made which automatically diffuses out of the cell
