Please answer questions 1-5, thank you very much!! 1. A) What is the difference
ID: 141318 • Letter: P
Question
Please answer questions 1-5, thank you very much!!
1. A) What is the difference between active and passive transport through membranes? B) What is the definitive characteristic of mediated transport? C) Give an example of each (active, passive, mediated) and explain why it serves as an example of that type of transport. 2. Explain the basic differences (in terms of their operation) between Inducible and Repressible enzyme systems 3. A) Outline the basic steps for DNA replication. B) Why is this type of replication termed 'semiconservative? 4 Outline the basic steps for A) Transcription and B) Translation. 5. A) Define point mutation. B) Explain the difference between frame shift and substitution mutations. C) Which kind is potentially more dangerous to health? D) Explain WHY E) Which type of mutation is sickle cell anemia based on?Explanation / Answer
1. A)
B) Mediated transport across the cell membrane is brought about by transmembrane protein. It is highly specific for a particular ion or molecule.
c) Examples:
Active: Sodium-potassium ATPase: this channel moves sodium and potassium against the concentration gradient with lysis of ATP.
Passive: Aquaporins: they are water channels that function as selective pores for the move of ions across the cell membrane.
Mediated: Cotransport(symport): sodium dependant glucose transport. The transporter carries two solutes in the same direction across the membranes.
2.
4. A) Initiation-Elongation-Termination-Processing.
B) Activation of amino acids-Initiation of protein synthesis-Elongation of polypeptide chain-termination-processing.
5. A) It is a type of mutation in which a nucleotide is replaced by another nucleotide on the gene sequence.
B) Frame shift muatation: There is either insertion or deletion of a new nucleotide in the sequence of a gene.
Substitution: In substitution, one nucleotide is replaced by another nucleotide in the gene sequence.
C) Frame shift is more dangerous.
D) Substitution may produce same protein or slightly altered protein which is functional as there is change in only a single codon. However, in frame shift mutation, there is change in the reading frame from the point of mutation which will produve a gene sequence which differs considerably from the original protein.
E) sickle cell anaemia is an example of point mutation.
Active transport Passive transport It moves ions/substances from lower to higher concentration. It moves ions from higher concentration to lower concentration. It requires energy(ATP) as the movement of ion is against the concentration gradient. It does not require ATP as the movement of ions is in the direction of the concentration gradient.