Lecture 18-19: Nucleic Acids Flashcards
(just by heart and weaknesses)
Functions of Nucleic acids (3)
- Genetic material
- Gene expression
- Gene regulation
Characteristics of genetic material
- Carry information
- Can be replicated
- Can be transmitted to offspring
- Can be changed by mutation
Information carried by genetic material
- genes
- info to regulate gene expression
- directions for DNA replication
Where is genetic material found?
DNA
Gene
units that encode polypeptides (and other products)
What are the two types of RNA
- non-coding RNA
- transfer RNA
What is said to be and “intermediate” between DNA and protein? Why?
mRNA
DNA-like: perform key function in info processing
Protein-like: functions as a catalytic molecule
What do you call an RNA that performs catalytic functions
a ribozyme
What happens during splicing in RNA processing?
The introns (non-coding parts of RNA) removed and exons (coding) joined tgt
Exceptions to the central dogma of gene expression
- Many genes encode functional RNA (non-coding RNA) and are used directly (don’t follow the process)
- some genes encode protein subunits which need to be combines with others to function
- reverse transcription: when info flows from RNA to DNA
Name the pyrimidines
cytosine, uracil (RNA), thymine (DNA)
Name the purines
guanine, adenine
Which is larger, pyrimidines or purines
purines
Components of nucleic acid
- phosphate group
- nitrogenous base
- 5-carbon sugar
What is the direction of the sugar-phosphate backbone of nucleic acids?
nucleic sequence written in 5’->3’ direction (nucleic acids added to 3’ end)