Area 1 Flashcards
What type of division do somatic cells do, to make more somatic cells?
Mitosis
What is a cellular differentiation?
When an unspecialised cells become specialised to have a particular structure and functions
How does the cell become differentiated?
Some genes are switched on and some genes are switched off, which means only a limited amount of genes are expressed.
What are stem cells?
They are unspecialised somatic cells which can self renew and differentiate into specialised cells
How do you grow some cells and use them to treat patient?
Remove stem cells from a patient, culture them in a lab and then put them back into the part where you remove them from
What are tissue stem cells useful?
Growth and repair and renewal of cells found in the tissue
What type of stem cell can be described as multipotent?
Tissue stem cells - Multipotent means that cells have a narrow differentiating potential, they can only develop into cells related from that tissue
What type of cells would develop from the red bone marrow?
Red blood cells, white blood cells, platelets
Embryonic stem cells are described as pluripotent. What does this mean?
They can differentiate into any type of cell in the body
What form of cell division do germline cells divide by to form more germline cell?
Mitosis
What form of cell division do germline cells divide by to form haploid gametes?
Meiosis 
Name therapeutic uses of stem cells?
To treat cancer, to treat corneal damage, bone marrow transplant, muscle repair, skin graft
What some future uses of stem cells?
Treat Parkinson is, Alzheimer’s and MS
What is cancer?
An uncontrolled cell division
Why do you cancer cells divide uncontrollably?
They do not respond to regulatory signals
Why does cancer spread sometimes?
The cancer cell fail to attach to one another and spreads throughout the body, via the bloodstream and forms a secondary tumour
How is DNA arranged?
It is tightly coiled and packed with proteins (histones)
What does DNA carry?
The genetic code
In what shape is the DNA found?
A double helix
How are the two DNA strands had together?
Hydrogen bonds
This strands run in opposite directions. What is the term used to describe this arrangement?
Antiparallel
What end is the deoxyribose sugar?
The 3’ (prime) end
What end is a phosphate end?
The 5’ (prime) end
What’s does a nucleotide compose off?
Phosphate, deoxyribose and a base
What are the four bases in DNA?
Adenine, thymine, Guanine, and cytosine
How does the strong chemical sugar phosphate backbone form?
From a strong chemical bond forming between the deoxyribose sugar of one nucleotide and the phosphate of the next
Name the base pairs?
Adenine + Thymine
Guanine + Cytosine 
Describe the process of replication?
- DNA is unwound and unzipped to form two template strand
- DNA polymerase needs a primer to start replication and can only add complimentary DNA nucleotides to the deoxyribose (3’) end of the DNA strand
- The results in one strand being replicated continuously and the other strands replicated in fragments which are joined by ligase
What are the phenotype determined by?
The proteins produced as a result of gene expression
Are all genes in the cell express?
No
Gene expression in those which two processes?
The regulation of both transcription and translation
Describe the structure of RNA?
- Single-stranded,
- it contains Uracil instead of thymine
- contains ribose instead of deoxyribose
What from the ribosome?
rRNA and protein
Describe the process of transcription?
RNA polymerase unwinds and unzips the DNA strand, breaking the hydrogen bonds between the strands. Complimentary RNA nucleotides align with the complimentary DNA nucleotide and on one strand. Hydrogen bonds form between the complimentary base pairs. Strong chemical sugar phosphate back bone forms. RNA polymerase joins RNA nucleotides to the growing strand of the mRNA at the 3’ end
Where does the transcription take place?
The nucleus
What are introns?
the non-coding regions of a gene/primary transcript
What are exons?
The coding regions of a gene/primary transcripts
Our introns or exons remove from a primary transcript?
Only introns are removed
What is the process of removing introns called?
Splicing
Explain why it’s important that the non-coding regions are removed from the primary transcript?
To ensure the correct protein is formed
Exons are joined together to form what?
The mature transcript / mature mRNA
Explain how a different protein can be produced from the same gene?
Different regions of the primary transcripts are treated as exons and introns and therefore different natural transcripts are formed from the same primary transcripts
What is the process of producing different mature transcripts from the same primary transcript called?
Alternative splicing
Where does translation take place?
The ribosome
What is a triplet of bases called on a DNA and mRNA strand?
Codon
What is the function of tRNA?
To transfer Specific amino acids to the ribosome
To align specific amino acids in the correct sequence in the protein
What two sites does the tRNA have?
An amino acid attachment site an anti codon
What is the anti codon of the tRNA complimentary to?
An mRNA codon
Describe the method of translation?
The mature mRNA joins to the ribosome.
tRNA transfers specific amino acids to the ribosome and aligns the correct amino acid in the sequence by aligning its anticodon with the complementary/matching codon on the mRNA strand
Hydrogen bonds form between the bases
Peptide bonds form between adjacent amino acids
A chain of amino acids called a polypeptide is formed.
How is it possible that different proteins are expressed from one gene?
Alternative spicing
What are proteins held together with?
They are held in a three-dimensional shape by a peptide bond, hydrogen bonds and interactions between individual amino acids
What shape do most proteins fold into?
Polypeptide chains folds to form the three-dimensional shape of a protein
What is a mutation?
An alteration to the original DNA sequence
What happens if a mutation occurs?
A faulty protein or no protein is made
Are mutations common?
No, they are random rare and spontaneous
Name the three Mutagenic agents
- Mustard gas
- UV rays/UV lights
- gamma rays
How do single gene mutations arrive?
SID By substitution, insertion or deletion
What is a substitution gene mutation?
A nucleotide is substituted for one another
What is the effects of a substitution gene mutation?
 the amino acid coded for could be a missense mutation or nonsense mutation. An incorrect protein will be made.
What is the misssense mutation?
The mutation still codes for an amino acid but not the correct amino acid
What is a nonsense mutation?
Do you mutation causes the code onto now code for a stop codon. This results in a short and protein/faulty protein being made.
What is an insertion gene mutation?
A nuclear tide is inserted into the DNA sequence?
What is the effect of an insertion gene mutation?
Frameshift mutation. All the codons after the point of mutation are altered and a faulty protein is made
What is a deletion gene mutation?
A nucleotide is deleted from the DNA sequence
What is the effect of a deletion gene mutation?
Frameshift mutation. All the codons after the point of mutation are altered and a faulty protein is made
What is a splice site mutation?
Slicing is controlled by specific nucleotides sequences at splice sites on those parts of the introns that are next to the extrons. If a mutation occurs at one of the splice sites, the codon for an intron-exon splice may be affected and an intron may be retrained in an error
What is the effect of a splice-site mutation?
A faulty protein is made
