Unit 5 Flashcards
(25 cards)
What are the 2 types of nucleic acids in cells?
DNA & RNA
What is a chromosome?
a long DNA molecule containing many proteins that carry portions of the hereditary information of an organism.
What is a gene?
Region of DNA that controls a hereditary characteristic.
it is a sequence of nucleotides on a chromosome that can :
- encode the production of a specific protein/RNA
- regulate the transcripts of such a sequence
- carry biological information in a transmittable and carriable form
What is the role of RNA?
DNA = in the nucleus
= programs protein production in the cytoplasm by dictating the synthesis of messenger RNA.
Each gene of the DNA directs synthesis of mRNA
The mRNA molecule interacts with the cell’s protein-synthesizing machinery to direct the production of a polypeptide.
What is the flow of genetic information?
DNA->RNA->Protein
What is the structure of a nucleotide (the 3 parts)?
- organic molecule: “nitrogenous base”
- A pentose (5 C sugar)
- Phosphate group
What are the two types of nitrogenous bases?
Pyrimidines
-> 1 six-membered ring of carbon and nitrogen atoms
-> Cytosine/Thymine/Uracil
Purines
-> six-membered ring fused to a five membered ring
-> Adenine/Guanine
What is the structure of a deoxyribonucleotide?
1 molecule of deoxyribose (with 1 OH and 1 H), 1 phosphate group and 1 nitrogenous base
What is the structure of a ribonucleotide?
1 molecule of ribose (with 2 OH), 1 phosphate group and 1 nitrogenous base
What type of bonds form the backbone of the nucleic acid polymer?
Backbone = phosphate group and sugar. the nitrogenous base is not part of the backbone
What type of bond holds the two strands of DNA together?
The 2 strands are held together by hydrogen bonds between the paired bases and Van Der Walls attractions between the stacked base pairs
H-Bond = strong enough to hold the strands together, yet weak enough to be broken apart
What is transcription?
What is tRNA (two functions + structure) ?
What is translation?
What is a reading frame?
What is an anticodon?
How many nucleotides does it take to code for one amino acid?
What does the fact that the genetic code is nearly universal, shared by organisms varying from the simplest bacteria to the most complex plant and animals
tell us?
What is complementary base pairing in nucleic acids?
Only certain bases in the double helix are compatible with each other;
A-T
G-C
What is the importance and function of complementary base pairing in nucleic acid structure?
It makes it possible to generate 2 identical copies of each DNA molecule in a cell that is preparing to divide
When the cell divides -> copies are distributed to the daughter cells, making them identical to the parent cell.
What are the base pairing rules for DNA and RNA?
What determines the primary structure?
Gene
->The aa’s sequence is programmed by a gene
Describe protein synthesis.
Each gene directs the synthesis of mRNA.
-> The mRNA interacts with the machinery of the cell that synthesizes protein.
-> It then directs the production of a polypeptide.
-> The polypeptide then folds into a protein.
DNA = in the nucleus
ribosomes = between nucleus and cytoplasm
mRNA transports genetic instructions for building proteins from the nucleus to the cytoplasm.
What is a nucleic acid?
Nucleic acid = polymer called polynucleotides
monomer of polynucleotides = nucleotide
