Exercise 1 Flashcards
There are two nucleic acids associated with the nucleus of the cell?What are these molecules composed of?
- These molecules are composed of nucleotides.
- List the three subunits of a nucleotide.
- The three subunits of a nucleotide are:
i) a phosphate (phosphoric acid)
ii) a pentose sugar
iii) a nitrogen containing base
- What is the function of DNA?
- The function of DNA is to store information controlling its own replication, and to store information concerning the order of placement of amino acids in a protein chain. This latter function is referred to as protein synthesis.
- What is the role of RNA?
- The role of RNA is to help in the process of protein synthesis. It does so by carrying the information it copies from the DNA concerning the sequencing of amino acids, to the ribosome where protein is actually built.
- What are the three main structural differences between DNA and RNA?
- The three main structural differences between DNA and RNA are:
i) the sugar molecule in DNA is a 5-carbon deoxyribose sugar; in RNA it is ribose sugar
ii) the base thymine is replaced by the base uracil in RNA
iii) DNA contains two strands; RNA contains only one strand
iv) the two strands of DNA are wound together forming a helix; the single strand of RNA does not form a helix
- Describe what a DNA molecule looks like.
- DNA is a double stranded molecule that looks like a flexible ladder that has been twisted into a spiral shape. The sugar and phosphate molecules form the sides of the ladder and the hydrogen-bonded bases make up the rungs of the ladder.
- A nitrogen base is one of the subunits of a nucleotide. Name the four different nitrogen bases found in DNA. Name the four nitrogen bases found in RNA.
- DNA contains four different nitrogen containing bases: adenine (A), thymine (T), guanine (G), and cytosine (C). RNA contains four different nitrogen containing bases: adenine (A), uracil (U), guanine (G), and cytosine (C).
- What does complementary base pairing mean?
- Complementary base pairing refers to the hydrogen bonding between certain bases. In DNA: adenine and thymine always bond together, guanine and cytosine always bond together
In RNA: adenine and uracil always bond together,guanine and cytosine always bond together.
- If one side of a DNA molecule has the nitrogen base sequence CCG TTA CGA, what is the corresponding base sequence on the other side?
- The corresponding base sequence on the opposite side is GGC AAT GCT. It’s placement on the rungs of the ladder would be as follows:
C-G
C-G
G-C
T-A
T-A
A-T
C-G
G-C
A-T
- What effect does the arrangement of the nitrogen bases in the DNA molecule have on the structure and function of a cell?
- It is the sequencing of nitrogen containing bases in a DNA molecule which forms the genetic code, determining the appearance and function of a cell. The sequence of nitrogen containing bases is the genetic information that will specify the sequence of amino acids that form a particular protein in a cell.
What are the two nucleic acids associated with the nucleus of the cell?
- The two nucleic acids associated with the nucleus of the cell are deoxyribonucleic acid abbreviated to DNA and ribonucleic acid abbreviated to RNA.
___________ is the study of heredity; the passing on of inherited traits
Genetics
____________ are the molecules DNA and RNA which are associated with the nucleus of the cell
Nucleic Acids:
_________ literally means “coloured bodies.” The units that contain DNA. ___________ is a short thick rod-like structure composed of a single long DNA molecule wound up tightly around protein molecules; a chromosome may be referred to as packaged DNA
Chromosome
________ is the basic unit of heredity; a gene is a short segment of DNA; each gene directs or controls the expression of a particular trait; e.g. hair colour
A Gene
