Chapter 6 Part 1 - Inheritance Flashcards
What is DNA?
- Deoxyribonucieic acid
- The molecule that carries our genetic information/ inheritance
Where is DNA found?
Chromosomes are made of DNA. Chromosomes are found in the nucleus.
What is a section of DNA called?
Gene
How many chromosomes are in each cell?
23 pairs (half from each parent)
What is meant by the word genome?
The entire genetic makeup of an organism
Explain the structure of one molecule of DNA
- It consists of 2 strands of repeating units called nucleotides
- These strands twist to create a double helix
What is one single nucleotide called?
monomer or mononucleotide
What are the three components of a mononucleotide?
- Phosphate
- Sugar
- Base
What is the bond called that holds the phosphate and sugar together?
Ester bond
What is the bond called that holds the base and sugar together?
Glycosidic bond
Mononuleotides can join together between the phosphate and sugar of different nucleotides. What is the new structure called?
Polymer or polynucleotide
What are the four bases?
- Adenine (purine)
- Guanine (purine)
- Cytosine (pyrimidine)
- Thymine (pyrimidine)
What are the two complimentary base pairs and what bonds hold them together?
- A and T (double hydrogen bond)
- G and C (triple hydrogen bond)
What is a codon?
A sequence of 3 bases that code for 1 amino acid
How many types of amino acid are there?
20
What are stop codons?
Stop codons signal the end of the chain has been reached during protein synthesis
What are the 3 types of RNA?
- mRNA = rewrites sequence of bases of a section of DNA (formed in nucleus)
- rRNA = ribosomes are made up of rRNA and proteins
- tRNA = pick up specific amino acids from cytoplasm to bring to the surface of a ribosome where they are joined in a specific order to make a specific protein
What are the two major processes in protein synthesis?
- Transcription: makes copy of the DNA called mRNA
- Translation: the mRNA is read by ribosomes to produce a protein
What are exons?
The coding parts of DNA
What are introns?
The non-coding regions of DNA
What determines what protein is formed?
The order and combination of bases determine which amino acids are made, and then the order and combination of the amino acids determines the protein created
What is a mutation?
A change in the sequence of DNA bases
How do mutations occur?
They are random and occur continuously.
What is the affect of mutations?
Can have no effect but can also seriously affect a protein as it could affect its ability to before its function e.g. enzyme with different active site.
