B1 Flashcards
What are the different parts of a eukaryotic cell?
(ANIMAL AND PLANT CELLS)
- NUCLEUS- Contains genetic material arranged into chromosomes
2.CYTOPLASM- Where most chemical reactions take place(because of enzymes
3.PARTIALLY PERMEABLE MEMBRANE- Holds the cell together, controls what goes in and out
4.MITOCHONDRIA- Contains enzymes needed to control aerobic respiration(energy transfer.
5.Ribosomes- Protein sythesis
What are the different parts of the prokaryotic cell?
(BACTERIA ETC)
NO NUCLEUS
1.Genetic material is one long circular chromosome floating in the cytoplasm
2. PLASMIDS- small loops of extra DNA
3. CELL MEMBRANE
4.CELL WALL
5.RIBOSOMES
What is the genome?
The entire genetic material of an organism
What is a chromosome?
A really long molecule of DNA, comes in pairs (humans have 23 pairs, 46 in total)
What is DNA?
-A polymer made up of monomers called nucleotides.
-Double helix
What are the 4 bases of DNA?
adenine thynine cytocine guanine( A T C G )
What is the polymer of a protein called?
amino acid-coded for by three bases
What is a triplet code?
three bases of DNA that connect together by a sequence.
Where are proteins synthesised?
In the cytoplasm
What is the transcription process?
(gene to mRNA to be able to leave the nucleus)
6 marker
- RNA polymerase binds to the DNA just before where the gene starts on the template stand. The DNA opens up ahead of it
2.RNA polymerase moves along the DNA strand reading the bases one at a time
3.As it moves, it matches a complimentary base pair to make a mRNA strand that carries the enclosed message
4.As RNA polymerase moves, DNA strand closes behind it, and opens up ahead of it until it has everything it needs.
5.RNA polymerase detatches and mRNA is free to go from nucleus to ribosome
What is translation?
(mRNA to protein, to be used in the body)
6 marker
1.mRNA travels to the ribosome. Each triplet codon on the mRNA codes for a specific aminon acid
2.mRNA and ribosome bind; amino acids are broughy by the tRNA
3.tRNA have an anticodon that they use for complimentary base pairing with the mRNA; if their anticodon matches, they deposit their amino acids
EACH tRNA is specific for one codon, and can only pick up one type of amino acid> (3 bases = 1 codon = 1 amino acid)
1.Once joined the ribosome moves along and tRNA detatch/ new tRNAs bind. Peptide bond form between aminon acids.
2. At the stop codon, the chain detatched from the ribosome, folds up on itslef and forms a protein
What is a genetic mutation?
A change to the genome.
What is an insertion mutation?
When a new base(A,T,C,G) is insertef into the DNA base sequence, changes the triplet codons, which changes the amino acid they code for
What is a deletion mutation?
When a base is removed from a DNA base sequence.
What is a substitution mutation?
A random base is replaced for another in the DNA base code. doesnt always change the amino acids in a protein
What is an allelle?
Different versions of the same gene
What is a dominant allele?
An allele with a capital letter
What is a recessive allele?
AN allele with a lowercase letter
What is homozygous?
When both alleles are the same(dd,DD)
What is heterozygous?
When the alleles are different(Xx)
What are gametes?
They are sex cells(sperm and egg cells) with half the usual number of chromosomes. Involved in reproduction
What is a phenotype?
The observable characteristics in an individual resulting from the expression of genes
What is genetic engineering, why is it used?
When the genome is modified to change an organisms characteristics.
What are cells?
The basic unit of life from which organs are made1
What is the purpose of the cell mebrane?
Protects the cell, controls what leaves and enters the cell
What is the purpose of the cell wall?
It gives structure to the plant cell
What is the purpose of the chloraplast?
It is the site of photosynthesis-where it takes place
What is the purpose of the cytoplasm?
Jelly like substance in the cell, where chemical reactions take place
What is the purpose of mitochondrion?
The powerhouse of the cell-where aerobic respiration takes place
What is the purpose of the nucleus?
To hold DNA of the cell
What is the purpose of the plasmid?
A loop of genetic material which can be transferred between cells(e.g to share genes for antibiotic resistance)
What is the purpose of the ribosome?
The site of proteinsynthesis(amino acids that come from DNA)
What is the purpose of the vacuole?
The storage sight of a cell, water storage, cell sap, energy and waste disposal
What is the purpose of the vacuole?
The storage sight of a cell, water storage, cell sap, energy and waste disposal
What is genetic engineering?
- Modifying the DNA of an organism to produce desirable characteristics
- It is used to give organisms new and useful characteristics
- Involves cutting a gene from one organsims genome and putting it into another organism genome
What are inherited disorders?
A group of conditions passed on in allelles
What is polydactly?
- A condition where baby is born with extra fingers or toes
- Does not cause other problems
- Caused by a dominant allelle(If one of the two alleles was polydactly then you may still be a carrier of the disease or have it)
What is cystic fibrosis?
- A disorder of cell membranes that resulst in thick sticky mucus being released into different parts of the body(only lungs and pancreas
- caused by recessive allele
- need two reccessive alleles to have disorder
What is an IVF?
- When egg cells are fertilised with sperm in a laboratory
- It is then implanted back into the woman to grow into a foetus
What is embryonic screening?
- When a doctor takes one of the cells from a fertilised embryo after an IVF to have a look at the genes to see if it carries any genetic disorders
- If allelles are found with the disortdet then parents and doctors may discard embryo and use a different one
- Advantages: reduces suffering, saves money from treating disorder
- Disadvantages:Implies people with disorders are less desirable, people may use screening for other traits
