L3 - The structure of DNA Flashcards
What is the double helix structure?
A deoxyribonucleic acid molecule consisting of two strands of nucleotides twisted together to form a double helix.
What are the 3 components a nucleotide is made up of?
- Phosphate groups
- A sugar
- A nitrogenous base (A, T, C, G)
What do the nitrogenous bases form? What are they held together by?
Nitrogenous bases form the rungs of the double helix ladder by pairing together. These are held together by weak hydrogen bonds that can be broken when the ladder ‘unzips’
What are the four types of Nitrogenous bases?
Adenine
Thymine
Cytosine
Guanine
What are Chromosomes?
Coiled thread of DNA wrapped around proteins found in the nucleus of all cells
What is a gene?
Length of DNA that codes for the making of particular proteins (more accurately - polypeptide chain)
What is a cell nucleus?
A membrane bound ‘command centre’ containing all the chromosomal and genetic information needed for the reproduction of life.
What is DNA?
Deoxyribonucleic Acid, instruction manual for protein production (The genetic code)
What is cytoplasm?
The fluid part of the cell outside of the nucleus that contains dissolved chemical substances, insoluble substances and suspended organelles.
What is a cell?
A cell is the smallest structural and functional unit of an organism
What is an allele?
An Allele is one of two variations of a gene at the same point in the chromosome
How many chromosomes are in an animal cell?
23 pairs, 46 in total
What happens if there is one more or one less chromosome?
It leads to deformations in the body
Where do the chromosomes live?
The nucleus of the cell
What are chromosomes made of?
Two individual strands linked together (also known as a chromatid).
A gene is a small section that makes up this chromosome - each gene coding for a different function (also known as alleles)
