5 Written questions
5 Matching questions
- RNA (characteristic)
- Mechanisms controlling transcription
- a DNA molecule is antiparallel -> Strands are oriented in opposite directions, strands differ at the ends 1) One strand oriented in the 5' to 3' direction. 2) The other strand is oriented in the 3' to 5' direction.
- b 1) RNA is made up of nucleotides -> Ribonucleotides 2) RNA contains nitrogenous bases -> Adenine, Guanine, Cytosine, Uracil (Uracil replaces thymine in RNA) 3) RNA usually exists as single stranded molecule 4) Portion of DNA acts of template for RNA synthesis -> Either strand of DNA can act as template 5) Three different functional groups of RNA mRNA, rRNA, tRNA
- c Messenger RNA -> type of RNA molecule that is translated during protein synthesis.
- d Ribosomal RNA -> type of RNA molecule present in ribosomes. rRNA builds the ribosomes
- e 1) Often controlled by regulatory region near promoter ->Protein binds to region and acts as "on/off" switch -> Binding protein can act as repressor or activator -> Repressor blocks transcription and Activator facilitates transcription 2) Set of genes controlled by protein is called an operon
5 Multiple choice questions
- 1) Strands are complementary to each other -> Due to the specific base pairing of bases -> A:T and C:G 2) Strands are held together with hydrogen bonds -> A is bound to T by two hydrogen bonds and G is bound to C by three hydrogen bond
- Process of synthesizing RNA from DNA template 1) mRNA carries the coded information from DNA to the ribosome, which is the site of protein synthesis 2) mRNA also plays an important role in translation 3) During transcription the enzyme, RNA polymerase, synthesizes a complementary strand of mRNA from a portion of unwound DNA
- Sequence of 3 nucleotides in a tRNA molecule that is complementary to a particular codon in mRNA. The anticodon allows the tRNA to recognize and bind to the appropriate codon.
- 1) Nucleotide sequence codes for regulation mechanism for gene expression 2) Mechanisms determine duration of synthesis of gene products -> Products are only made when required 3) Key mechanism is regulation of mRNA synthesis from DNA -> Regulation of transcription
- 1) Involves two separate but interrelated process, transcription and translation 2) RNA polymerase binds to a region of the DNA called the promoter 2.1) Only one strand of DNA acts as a template 2.1.1) This is called the sense strand 2.1.2) The strand not transcribed is the nonsense strand 3) Nucleotides in RNA are the same as those in DNA with one exception 3.1) Thymine is replaced with uracil 3.1.1) Binding in RNA is A:U or U:A and C:G or G:C 4) RNA polymerase continues down strand of DNA until it reaches a site on DNA called the terminator -> At the terminator RNA polymerase and the new strand of mRNA are released from strand of DNA 5)
5 True/False questions
Nucleotides → Includes 1) Phosphate group 2) 5 carbon sugar -> Deoxyribose 3) Nucleotides bond covalently between the 5'PO4 of one nucleotide and the 3'OH of another -> Joining of nucleotides creates an alternating sugar-phosphate backbone
Inducible enzymes → 1) Routinely synthesized 2) Generally involved in biosynthesis
Terminator → Transfer RNA -> type of RNA molecule that acts as a key, interpreting the genetic code; each tRNA molecule carries a specific amino acid. tRNA recognizes specific sequences of mRNA and transports the required amino acids to form a polypeptide chain
Central dogma of molecular biology → 1) Not all genes subjected to regulation 2) Enzymes can be classified according to characteristics of regulation 2.1) Constitutive enzymes 2.2) Inducible enzymes 2.3) Repressible enzymes
Principles of regulation → 1) Not all genes subjected to regulation 2) Enzymes can be classified according to characteristics of regulation 2.1) Constitutive enzymes 2.2) Inducible enzymes 2.3) Repressible enzymes