Chapter 4 Notes Flashcards
(28 cards)
The nucleic acids
DNA and RNA
DNA is polymer of
Nucleotides
Nucleotides consist of:
Sugar, Phosphate group, and nitrogenous base.
Nitrogenous bases are:
Cytosine (C), Thymine (T), adenine (A), and guanine (G)
DNA is described as a
Double helix resembling a spiral staircase
Each side piece is composed of?
Phosphate groups alternating with deoxyribose (sugar)
The step like connections are pairs of?
Nitrogenous bases (A-T, G-C) which hold the side pieces together with hydrogen bonds.
The essential function of the DNA and RNA is to:
Carry out instructions for the synthesis of proteins.
RNA consists of how many nucleotide chains?
Only one
The sugar is what?
Ribose
RNA has no what?
No thiamine but uracil takes its place.
mRNA
the molecule that carries the genetic code from the nucleus to the cytoplasm
tRNA-
Binds a free amino acid and delivers it to the ribosome.
Ribosome is?
The molecule that reads the mRNA
Gene -
An information-containing segment of DNA that codes for the production of a molecule of RNA
Genome
All the Dna in a set of 23 pairs of Chromesomes
Transcription
The process of copying genetic instruction from DNA to a complementary RNA
Translation
The process of reading the mRNA and synthesizing he protein encoded in the nucleotide sequence
Initiation
I. mRNA outside the nucleus forms a loop
II. The ribosomal subunits and the initiator tRNA bind to the mRNA
III. The ribosome begins sliding along the mRNA reading bases
Elongation
I. The tRNA that matches the next sequence on the mRNA binds to the ribosome
II. The amino acid for the previous tRNA binds to the new amino acid on the new tRNA
III. The ribosomes reaches the stop sequence on the mRNA and the previous tRNA leaves the ribosomes
Termination
The ribosome reaches the stop sequence on the mRNA and releases from the mRNA
DNA Replication
- Double helix upward
- The enzyme DNA polymerase moves along the strand, reads the exposed base and arranges a match with complimentary free nucleotides
- Each old (parental) strand has a new (daughter) complementary strand Resulting in two identical copies of daughter DNA
Mitosis (cell division)
- Functions
a. Development of an individual
b. Growth of tissues and Organs after birth
C. Replacement of cells
D. Repair of damaged tissue.
Prophase
I. Chromosomes coil into compact rods which consist of two identical sister chromatids
II. The nuclear envelope disintegrates.