Biology 18.1 DNA Structure/ Replication Flashcards
DNA (6)
(Deoxyribonucleic acid)
- DNA is responsible for storing and transferring genetic information, Long-term storage of genetic information; transmission of genetic information to make other cells and new organisms
- codes for traits (Blood type/ hair colour)
- AT CG
- Found in nucleus
- Double stranded (runs antiparallel between the two strands)
RNA (6)
(Ribonucleic Acid)
- RNA directly codes for amino acids and acts as a messenger between DNA and ribosomes to make proteins.
- A nucleic acid that plays a role in gene expression and protein synthesis
- Found in and out of nucleus
- AU GC
- Used to transfer the genetic code from the nucleus to the ribosomes to make proteins.
Transfoming principle
Term given to the substance that could be transferred from non living cells to living cells, causing the living cell to show characteristics of the non living cell.
- Federick Grifft
Phoebus Leven (1900s)
- Genes are located on chromosomes
- Chromosomes are made up of DNA and proteins
- Isolaed 2 types of nucleic acid (RNA/ DNA)
- nucleotides
DNA nucleotide
- a five carbon sugar
- a phosphate group
- one of five nitrogen containing bases.
Structure of DNA/ RNA
- Both are made up of long chains of individual units he called nucleotides
- Both DNA/ RNA contain a combination of four different nucleotides
- Nucleic acids are made up of long chains of nucleotides strung together
Chargaff’s rule
- in DNA there is always equality in quantity between the bases A and T and between the bases G and C.
Rosalind Franklin
- Used X rays to analyze the structure of DNA (provided crucial new information about the molecular structure of DNA and concluded that:
1. DNA has a helical structure with 2 regularly repeating patterns
2. Nitrogen bases were located on the inside of the helical structure and sugar phosphate backbone on the outside facing towards the watery nucleus of the cell
The Double helix structure of DNA
- DNA is a thread-like molecule, made up of two long strands of nucleotides that are bound together in a spiral shape called a double helix
- From Franklin’s images, Watson and Crick knew that the distance between the sugar-phosphate handrails remained constant over the length of the molecule.
- Using Chargaff ’s rule, Watson and Crick hit upon the idea that an A nucleotide on one chain always sits across from a T nucleotide on the other chain, while a C nucleotide onone chain always sits across from a G nucleotide on the other chain. Thus, the two handrails maintain a constant total distance of three rings.
- As you can see in Figure 18.6, the two strands of DNA that make up the double helix are not identical. They are complementary to each other. You can always deduce the base sequence on one strand from the base sequence on the other strand.
- The two strands are antiparallel, as well. That is, the phosphate bridges run in opposite directions in
the two strands. Each end of a double- stranded DNA molecule contains the 5’ end of one strand and the 3’ end of the complementary strand.
purines
Adenine and guanine are derived from the family of compounds known as purines, which have a double- ring structure.
pyrimidines
Thymine and cytosine are derived from pyrimidines, which have a single-ring structure.
The complementary base pairs
The A-T and C-G pairs are called complementary base pairs. The complementary base pairs are held together by hydrogen bonds.
RNA
- Nucleic acid
- Sugar component of RNA is ribose rather than deoxyribose
- does not have nucleotide thymine but has uracil
- Single stranded
Genome
the entire set of DNA instructions found in a cell
Each strand of DNA serves as a template_____
for the creation of its complementary strand
