4 Basic Genetic Mechanisms Flashcards
it is important in the normal functioning of the body.
synthesis of proteins
-is the basis for the synthesis of proteins.
-It serves as the template to direct its replication and also provides the blueprint for the synthesis of proteins by its ability to direct the process of transcription and translation.
-consists of a chain of four kinds of nucleotides based on the type of nitrogenous bases.
DNA
is composed mostly of chromosomes, structures that provide the inherited and individual characteristics of an animal.
nucleus
DNA is made up of
two long polynucleotide chains.
Each nucleotide is composed of
one molecule of phosphoric acid
one molecule of deoxyribose
one of the four bases.
In the nucleus, the cell’s machinery copies the gene sequence into messenger RNA (mRNA), a molecule that is similar to DNA. Like DNA, mRNA has four nucleotide bases - but in mRNA, the base uracil (U) replaces thymine (T)
TRANSCRIPTION
-The protein-making machinery, called the ribosome, reads the mRNA sequence and translates it into the amino acid sequence of the protein. The ribosome starts at the sequence AUG, then reads three nucleotides at a time. Each three nucleotide codon specifies a particular amino acid. The “stop” codons (UAA, UAG and UGA) tell the ribosome that the protein is complete.
-is the formation of the polypeptide from mRNA.
TRANSLATION
This process is described to be semiconservative because each strand of a DNA double helix serves as a template for the synthesis of a complementary strand of DNA and each new DNA molecule consists of one old strand and one new strand.
DNA Replication
DNA replication starts with ____(what enzyme) unwinding of two strands by ____ formed between the complementary bases.
DNA helicase
breaking hydrogen bonds
what keeps DNA strands from binding again the whole topoisomerase preventing the supercoiling of the single strand of DNA.
Single-stranded binding proteins (SSBPs)
what is the enzyme that binds to the single-strand DNA attaches free nucleotides into a new strand of DNA based on complementary base pairing in a strictly 5’ to 3’ direction.
DNA polymerase
*DNA Replication
The unwinding of the double-stranded DNA forms two strands of DNA in two different directions called the
leading strand
lagging strand
*DNA Replication
the new strand is assembled continuously
leading strand
*DNA Replication
What do you call the new DNA strand that is assembled in many pieces (Okazaki fragments)
lagging strand,
enzyme that seals the pieces of a lagging strand
DNA ligase
is a segment of a DNA molecule that contains the information required for the synthesis of a functional biological product (protein or RNA).
gene
-sugar of a slightly different composition used in the formation of RNA
-contains an extra hydroxyl ion appended to the ribose ring structure.
ribose