Genetics Flashcards
What is the nucleus and what does it contain ?
The nucleus contains the
cell’s genetic material and it
acts as the ‘brain’ of the cell.
The nucleus contains DNA.
Zoom in on the nucleus
The nucleus is
surrounded by a nuclear
envelope
Chromatin is made of
DNA, arranged as
chromosomes
What is a gene ?
A gene is a section of DNA that codes for a specific protein.
It is the unit of heredity, and may be copied and passed on to the next
generation.
What is a chromosome ?
The cell’s nucleus contains chromosomes. These are long threads of DNA, each made up of many genes.
DNA
The chemical that carries the genetic code which determines the
characteristics of a living organism
- Instructions to put an organism together and make it function - DNA codes for proteins
Structure of DNA
● It is made up of two strands coiled together
● The two strands form a ‘double helix’ shape
DNA Bases
T, thymine A, adenine G, guanine C, cytosine A and T C and G
DNA is a polymer and is made from…
DNA strands are polymers made up of lots of repeating units called ‘nucleotides’ which are monomers
What does a nucleotide contain…
Each nucleotide consists of:
One sugar molecule
One phosphate molecule
One ‘base’
How do the nucleotides affect the structure of DNA ?
They link up with other nucleotides to form a
strand.
This strand joins with another strand to form
the double-helix
What is the function of sugar and phosphate in the structure of DNA….
The sugar and phosphate molecules in the
nucleotides form a ‘backbone’ to the DNA
strands.
Is the order of the bases important?
Yes!
It determines which protein is produced
It decides the order of amino acids
What do amino acids do to from proteins ?
Amino acids join together to form proteins
The order of amino acids in a chain determines which protein is produced
What does each sequence of three bases code for ?
Each sequence of three bases codes for a
different amino acid
eg, ‘GGT’
Some parts of DNA do not code for proteins- what do you think they do?
- Switch genes on and off
- Control whether a protein is made
Genes role in protein synthesis
- Each gene codes for (tells the cell to make) a particular chain of amino acid
- Genes also determine the specific order of amino acids, which determines the
type of protein produced - Amino acids join together to make a proteins