BIO302 Midterm Current Solved Paper Spring 2023

FOR MORE VU DATA VISIT MY website: · BIO302 Current Midterm spring 2023 · solve BY MAS All Rounder

Q1. Chargaff’s rule?

Chargaff's rule states that in DNA, the amounts of adenine (A) are same to the amounts of thymine (T), and the quantities of guanine (G) are same to the amounts of cytosine (C). This rule became important because it furnished critical evidence for the bottom pairing in DNA and helped in elucidating the structure of DNA.

Q2. Characteristics of genetic material?

The characteristics of genetic material include:

• It consists of and stores genetic records.
• It undergoes replication to skip at the genetic statistics to the subsequent generation.
• It is capable of undergoing mutations, which make contributions to genetic version.
• It may be expressed and transcribed into purposeful molecules which include RNA and proteins.
• It is subject to regulation and interacts with other cellular components to carry out various features.

Q3. Telomerase and its function?

Answer?

Telomerase is an enzyme that is involved in retaining the length and integrity of telomeres, which can be protective structures discovered on the ends of chromosomes. Telomerase adds repetitive nucleotide sequences to the telomeres, stopping their shortening at some point of DNA replication. Its predominant characteristic is to counteract the slow shortening of telomeres that takes place with every spherical of DNA replication, thereby preventing genomic instability and cellular senescence.

Q4. Chemical composition of protein?

Proteins are composed of amino acids, which might be related together through peptide bonds. The chemical composition of a protein includes carbon (C), hydrogen (H), oxygen (O), nitrogen (N), and occasionally sulfur (S). Amino acids comprise an amino organization (-NH2), a carboxyl group (-COOH), and a facet chain (R-institution) that varies among different amino acids. The sequence and arrangement of amino acids decide the shape and function of a protein.

Q5. Why Cisplatin is cytotoxic and act as chemotherapeutic agent?

Cisplatin is cytotoxic and acts as a chemotherapeutic agent because it forms covalent bonds with DNA, leading to the formation of DNA adducts. These adducts because DNA crosslinking, DNA strand breaks, and interfere with DNA replication and transcription. By inducing DNA harm, cisplatin disrupts the cellular cycle and triggers apoptosis, ultimately leading to the loss of life of cancer cells.

Q6. Role of 8 Oxo guanine?

8-Oxo guanine is a changed form of guanine which could end result from oxidative harm to DNA. It is a mutagenic lesion and can cause the mispairing of nucleotides in the course of DNA replication, inflicting G:C to T:A transversions. Eight-Oxo guanine is diagnosed and repaired through unique enzymes concerned in base excision repair (BER) to maintain genomic integrity.

Q7. End of replication error?

Answer

End of replication error refers to the unfinished replication of the very give up of a linear DNA molecule at some point of DNA replication. Due to the mechanism of DNA replication, the final segment of the lagging strand, known as the telomere, cannot be fully replicated. As a result, it leads to the sluggish shortening of telomeres with every spherical of replication. Telomerase enables to counteract this shortening by way of including repetitive sequences to the telomeres.

Q8. Name three proteins that catalyzes the direct alkylation?

Three proteins that catalyze direct alkylation are:

• DNA alkyltransferase (additionally referred to as O6-methylguanine-DNA methyltransferase or MGMT): It upkeep O6-alkylguanine adducts.
• AlkB homologs (ALKBH): They repair alkylated bases, together with 1-methyladenine and three-methylcytosine.
• Ada protein: It maintenance O6-methylguanine and O4-methylthymine adducts.

9. 2. How can one differentiate between pentose of ribose and

deoxyribose?

Ribose and deoxyribose are exceptional sugars located in nucleotides. Ribose is the sugar factor of ribonucleotides, which can be the constructing blocks of RNA. Deoxyribose is the sugar aspect of deoxyribose nucleotides, which might be the constructing blocks of DNA. The principal distinction between them is that ribose has a hydroxyl organization (-OH) attached to its 2' carbon, at the same time as deoxyribose has a hydrogen atom (-H) connected to its 2' carbon.

Q10. Name the origin of DNA, where alkylation occurs?

Alkylation can arise at numerous sites in DNA, however one distinguished web page is the O6 function of guanine. Alkylation at this function can result in DNA damage. One beginning of alkylation in DNA is publicity to alkylating marketers present within the surroundings or positive chemotherapeutic capsules, along with cisplatin.

Q11. 4. Watson and Crick work?

Watson and Crick's paintings refers to the groundbreaking discovery of the shape of DNA. In 1953, James Watson and Francis Crick proposed the double helix model of DNA, which defined the molecule as a twisted ladder with complementary base pairing and antiparallel strands.