B3 - Living And Growing Flashcards
Name the structure of a animal cell
- Nucleus (contains DNA in the form of chromosomes)
- Cell Membrane (holds the cell together and controls what is entering and exiting)
- Ribosomes (where proteins are synthesised)
- Cytoplasm (where most chemical reactions happen)
- Mitochondria (respiration takes place and where energy is produced)
Name the structure of a plant cell
- Nucleus (has the DNA)
- Cytoplasm (chemical reactions happen)
- Cell wall (supports the cell)
- Vacuole (contains the cell sap)
- Cell membrane (hold the cell together and controls what enters and exits)
- Chloroplast (where she photosynthesis happens)
What is the structure of a bacteria cell?
- Cell membrane (holds it together and controls what is entering and exiting)
- Cell wall (supports the cell)
- Cytoplasm (where chemical reactions happen)
- Bacterial (single strand of DNA moving freely)
What are chromosomes?
Long molecules of coiled up DNA
What is a double helix?
Two of the strands make up groups called nucleotides
What are the four bases? (Molecules which the nucleotides contain)
A, T, C, G
All Trees Can Grow
What bases can pair up with which?
A and T
C and G
What are genes?
Short sections of DNA
Who made the first model of DNA?
Watson and Crick
How does DNA replicate itself?
1) Molecules of DNA unzip
2) Bases join up with the other bases on the nucleotides
3) Cross links are formed to make another DNA strand
How are proteins made?
They are made by reading the code of the DNA and then making amino acids which attach together to make proteins
Summarise protein synthesis
1) DNA unzips
2) mRNA carries the code from the nucleus to the ribosomes
3) In the ribosomes 6 bases are chosen
4) The 6 bases make two amino acids
5) The amino acids are put together to make proteins
What are the four main functions of a protein?
1) Enzymes (act as biological catalysts)
2) Carrier molecules (transports smaller molecules like haemoglobin)
3) Hormones (carry messages around the body)
4) Structural proteins (strengthens things like tissue)
What are enzymes used for?
They are used as biological catalysts, which speed up a reaction without being used up or changing the reaction
How do enzymes do their job?
In an enzyme they have an active sight that is the same shape as the substrate (molecule being split)
When the substrate fits in and is released there is two products and an unchanged enzyme
What conditions do enzymes like?
Warm because if it is too hot then they will denature and if it is too cold they will not work
What pH do enzymes like?
Neutral as if it is too high or low then it will interfere with the bonds
What is Q(10)?
This is the value that shows how much the rate changes when the temperature is raised by 10 degrees
What is the equation for Q(10)?
Q(10) = rate at higher temperature / rate at lower temperature
What are gene mutations?
This is the change in DNA base sequences
How do you get mutations with radiation?
If a cell is hit with a high dose of ionising radiation this can cause mutations
What are some of the advantages with being multicellular?
- Bigger size
- More complex
- Cell differentiation (lot of things being done)
What is mitosis?
Mitosis is when a cell reproduces itself by splitting to form two identical offspring
What does mitosis do?
This replace body cells like tissue
What happens in mitosis?
1) The DNA goes into double armed chromosomes
2) They line up in the middle of the cell
3) Cell fibres pull them apart to opposite ends
4) Cytoplasms divide getting two new cells exactly the same
What is meiosis?
Meiosis is a cell division that creates gametes