Cells 1 (basic) Flashcards
What structure seperates the nucleus from the cytoplasm of the cell?
The double membrane that is the nuclear envelope
How does traffic move into and out from the nucleus?
Through nuclear pores, which bridge the double envelope
How many nucleotide pairs are there in the human genome?
3 billion
What percentage of the human genome encodes proteins and structural RNAs?
Less than 2%
What name is given to the regions of DNA which stabilise the ends of chromosomes?
Telomeres
What name is given to sequences of DNA that direct the distribution of chromosomes to daughter cells in cell division?
Centromeres
What proteins turn on/off genes in response to genetic, developmental and environmental signals?
Transcription factors
Which enzyes make RNA copiesof active genes in the process of transcription?
Polymerases
Which molecules specify amino acid sequences of proteins?
mRNA
What 3 processes do RNAs undergo before being used?
Alteration of bases
Removal of intervening sequences
The addition of specific chemical groups
Where are ribosomes assembled?
In the nucleolus
What do ribosomes catalyse, using mRNA as a template?
The synthesis of proteins
What is the name of the continuous system of flattened membrane sack and tubules in the cell?
Endoplasmic reticulum
How is the ER dynamic?
Motor proteins cause movement of microtubules
Which two structures have continuous bidirectional traffic between them in the form of molecules inside vesicle?
Golgi apparatus and endoplasmic reticulum
