biology prac Flashcards
What does DNA stand for
deoxyribonucleic acid
What are the components of DNA
phosphate , deoxyribose sugar, nitrogenous base
Which nitrogenous bases are pyrimidines
Cytosine (C) and Thymine (T)
What nitrogen bases are purines
Adenine (A) and Guanine (G)
What are pyrimidine nitrogenous bases
single ring 6 atoms
what are purines
double ring (9 atoms)
What is the function of RNA polymerase I
rRNA synthesis
What is the function of RNA polymerase II
mRNA synthesis
What is the function of RNA polymerase III
tRNA synthesis
what are some environmental factors that can contribute to cancer
- diet
- smoking
- drinking
- exercise
- mental health
- radiation
- chemical agents
What has caused the changes between cell A and cell B
Cell A – DNA repair mechanisms are working
Cell B – DNA repair mechanisms are broken
How many cells are required to give rise to cancer
1
What genetic changes lead to the development of cancer, and what other factors may be involved?
Gain of function mutation in protooncogenes
Loss of function mutation in tumour suppressor genes
These mutations lead to a loss of control of the cell cycle
Name + function
Helicase - unwinds the parental double helix
Name + function
Single strand binding protein - stabilize the unwound template strands
Name + function
leading strand - is synthesized continuously in the 5’ to 3’ direction by DNA polymerase III
Name + function
Primase - begins synthesis of the RNA primer
Name + function
DNA polymerase III - synthesizing DNA
Name + function
DNA polymerize I - removed the primer from the 5’ end and replaces it with DNA nucleotides
Name + function
DNA ligase - joints the 3’ end of the second DNA fragments to the 5’ of the first fragment
What is mRNA
messenger RNA and is used in translation to synthesize protein
what is tRNA
transfer RNA brings the corresponding amino acid in the ribosome during transcription
What is rRNA
ribosomal RNA comprises the ribosome
What are transcription regulation methods
- Transcription factors (promoter, enhancer, silencer)
- Chromatin packaging - Methylation and acetylation
- Epigenetics modifications
What are translation regulation methods
- Transcription regulation
- RNA degradation – half life, miRNA, siRNA,
- Translation factors
- Post translation modification – ubiquitination
CAP site
Promoter
Operator
Lac repressor protein
RNA polymerase II
CAP - Catabolite activator protein
cAMP
Allolactose
What factors may help determine whether a cell proceeds tot he S phase - passing G1 checkpoint
- growth factors activated
- sufficient number of organelles
- no TGFB proliferation inhibitor
- sufficient ATP present
What occurs in metaphase
the chromosomes align along the metaphase plate in the middle of the cell and the centrosomes are now at opposite ends of the cell. The chromosomes are now attached to a centrosome at opposite ends of the spindle.
What occurs in anaphase
The cohesion proteins binding the 2 daughter chromosomes are cleaved allowing them to move independently towards opposite spindle poles sister chromatids separate
What are the 2 main events that happens during telophase
Chromosomes de-condensation – 2 daughter nuclei form in the cell as the chromosomes become less condensed
Cytokinesis – the cytoplasm and organelles are divided resulting in the splitting of 2 daughter cells.
What happens to the chromosomes during prophase. Why is this important for cell division
Spindles form from centrosomes, and chromosomes condense. The condensation is important to ensure that during anaphase the cells genome is perfectly split and the correct genome is equally distributed between the daughter cells. This prevents the formation of genetic disorders.
What are the 2 phases of cell cycle
Interphase
Mitotic phase
