Chromosones, Genes & DNA, Protein Synthesis

Question 1

What are chromosomes?

Answer 1

Long strands of DNA found in the nucleus.

Question 2

What is the genome?

Answer 2

The entire DNA of an organism.

Question 3

What is a gene?

Answer 3

A section of a DNA molecule that codes for a specific protein that causes a certain characteristic.

Question 4

Structure of a DNA molecule:

Answer 4

Two strands coiled to form a double helix
Polymer made up of nucleotides
Nucleotide is made up of pentose sugar, phosphate group and an organic base (A, C, G or T)
Strands linked by base pairing: adenine with thymine, cytosine with guanine
Each group of three bases codes for an amino acid

Question 5

What does DNA stand for?

Answer 5

Deoxyribonucleic acid

Question 6

How is RNA different from DNA?

Answer 6

It is single stranded and contains uracil (U) instead of thymine (T)

Question 7

What are the 3 types of RNA?

Answer 7

tRNA (transfer RNA)
mRNA (messenger RNA)
rRNA (ribosomal RNA)

Question 8

What are the stages of protein synthesis?

Answer 8

1. DNA helix is untwisted and unzipped.
2. Transcription: mRNA nucleotides match to complementary bases, mRNA nucleotides are joined together, forming a template strand of the original DNA.
3. Translation: the template strand moves out of the nucleus and onto structures called ribosomes, where the codons code for one amino acid. tRNA molecules with complementary anticodons line up opposite the mRNA codons, forming a peptide bond.
4. Carrier molecules bring the corresponding amino acids, which join to form a protein.

Question 9

Features of mRNA:

Answer 9

Single chain of nucleotides
Four bases: adenine, cytosine, guanine and uracil
Each group of three bases is called a codon