DNA Flashcards
What is the basic unit of DNA? How is it formed?
Nucleotide, made up of a sugar, phosphate and a base (A, T, C, G)
What are the four bases in DNA?
Adenine, Thymine, Cytosine, Guanine
True or False: DNA is double-stranded.
True
Fill in the blank: The two strands of DNA are held together by ______ bonds between the bases.
hydrogen
What is the shape of the DNA molecule?
Double helix
What does the term ‘complementary base pairing’ refer to?
The specific pairing of adenine with thymine and cytosine with guanine.
What is the role of mRNA in protein synthesis?
To carry the genetic information from DNA to the ribosome.
Which process involves the synthesis of RNA from a DNA template?
Transcription
What is the primary function of ribosomes in the cell?
To synthesize proteins.
During which process are amino acids assembled into proteins?
Translation
True or False: Each amino acid is coded for by a sequence of three bases (called a _____)
Codon, True
What are the two types of RNA involved in transcription and translation
mRNA, tRNA
Fill in the blank: The sequence of nucleotides in DNA determines the sequence of ______ in a protein.
amino acids
What is the function of tRNA?
To transport amino acids to the ribosome during protein synthesis.
What is a codon?
A sequence of three bases on mRNA that codes for a specific amino acid.
True or False: DNA can leave the nucleus.
False
What process occurs in the nucleus during protein synthesis?
Transcription
What is transcription
In order to make proteins, DNA must be copied. mRNA (messenger RNA) is a single stranded copy of DNA.
1.The DNA is unzipped by breaking the hydrogen bonds between bases (helicase enzyme)
2. The RNA polymerase attaches to the now exposed DNA strand in a non coding region
3.Free RNA nucleotides now form hydrogen bonds with the bases (Thymine is replaced with Uracil), this is called a complementary copy)
4.The mRNA now leaves the nucleus and goes to the ribosome
What is Translation
- The mRNA enter the ribosome and attaches
- For every 3 bases (codon) there is one molecule of tRNA called the triplet code
- Each molecule of tRNA brings one specific amino acid which are left behind after lining up with the mRNA
- Used tRNA goes back collect another amino acid
- Eventually, a long chain of hundreds of amino acids is created called a polypeptide
- It is bent/folded into the right shape to become a protein
What is a chromosome
A tightly coiled strand of DNA
Humans have 23 pairs
What is a gene
A section of DNA that codes for one characteristic
Put these in size order: nucleus, gene, nucleotide, chromosone
Nucleus, chromosome, gene, nucleuotide
