DNA Flashcards
(28 cards)
What are Nucleic Acids and name the two different types.
-Nucleic Acids are organic molecules that control the synthesis of proteins and transferring of genetic info.
-Two types:
-DNA (deoxyribonucleic acid)
-RNA (ribonucleic acid)
Where is DNA found?
-Mainly occurs in the nucleus in the form of chromosomal DNA
-Can also occur in the mitochondria and chloroplast and is called Extranuclear DNA
Structure of DNA
-state whether it is single or double stranded.
-state the parts of the nucleotide.
-DNA is double stranded to form a double helix
-Nucleotide consists of three parts
-sugar molecule - deoxyribose
-phosphate group
-nitrogenous base
What are the different nitrogenous bases for DNA (4 types)
How do they pair?
Large Molecules = purine bases:
-Adenine (A)
-Guanine (G)
Small Molecules = pyrimidine bases:
-Cytosine (C)
-Thymine (T)
They will pair as:
A - T
G - C
Definition of Gene
Short segments of DNA with a specific sequence of nitrogenous bases.
What does DNA carry?
DNA carries genetic code for the synthesis of proteins.
What percentage of DNA in living cells code for proteins?
What does the remaining percentage do and what is it called?
~2% of DNA in living cells codes for proteins
- The other 98% is called Non Coding DNA
(Junk DNA)
What does Junk DNA do?
It is used in fingerprints
What does mtDNA stand for and what does it code for?
Mitochondrial DNA - mtDNA
- circular in shape
- codes for the enzymes that control cellular respiration.
What does RNA stand for and where is it found?
-RNA stands for ribonucleic acid
- it is found in the nucleus and cytoplasm and in some parts of ribosomes
RNA structure
-State whether it is double or single strand
-State the parts of the RNA nucleotide
-Single strand
-Nucleotide
-Sugar molecule - ribose
-phosphate group
-Nitrogenous bases
What are the different nitrogenous bases for RNA? (4 types)
How to they pair?
Large Molecules = purine bases:
-Adenine (A)
-Guanine (G)
Small Molecules = pyrimidine bases:
-Cytosine (C)
-Uracil (U)
A - T
U - A
G - C
C - G
What are the different types of RNA
- Messenger RNA (mRNA)
- Transfer RNA (tRNA)
- Ribosomal RNA (rRNA)
-What is the structure of mRNA?
-Where is it formed?
-What does it do?
- Single Strand with unlimited nucleotides
- Formed in the nucleoplasm using DNA as template
- Carries genetic code from DNA in the nucleus to ribosomes in the cytoplasm
-nitrogenous bases on the mRNA - codon
What is the structure of tRNA?
Where does it occur
What are the three exposed bases called?
What does it do?
-It is single stranded that folds in on itself to form loops.
-Occurs in the cytoplasm
-The three exposed bases are called anticodon
-It picks up amino acids and takes them to the ribosomes.
What is DNA Replication necessary for?
It is necessary for cell division.
DNA is duplicated to form?
DNA is duplicated to form 2 identical copies.
What are the identical copies called?
What else will duplicate?
-The identical copies are called chromatids.
- The histones also duplicate
When does DNA replication take place?
- Takes place during interphase
What is protein synthesis?
-Protein synthesis is the process in which proteins are manufactured in living cells
What controls the synthesis of proteins?
What are proteins made up of?
- DNA and RNA control the synthesis of proteins.
- proteins are made up of amino acids.
In order to make a certain protein, specific types of amino acids needs to be joined in a specific sequence.
Where does this sequence come from?
The sequence comes from our DNA (genes)
What provides a code for a particular amino acid?
-Codon
- they determine the sequence in which amino acids will link
What are the steps in protein synthesis?
-Transcription of DNA
-Translation of RNA to proteins.
