Answer:
Explanation:
Aerobic respiration is a set of metabolic reactions that take place in the presence of oxygen, occurring in a cell to convert chemical energy into ATPs. Anaerobic respiration is a process of cellular respiration where the high energy electron acceptor is neither oxygen nor pyruvate derivatives.
Answer:
The correct answer is: d. progressive stabilisation of correct secondary structural intermediates, and unfolding of incorrect structures, until the final structure is attained.
Explanation:
- Protein folding is a sequential process and not a random one.
- It is necessary that a protein must fold in such a way that in the end it is able to attain the particular conformation which is required for its function.
- The folding of an amino acid sequence is a process that is thermodynamically favourable.
- This is because in a folded protein the hydrophobic amino acids escapes from interacting with water molecules and hence gets stabilised.
- A folded protein has lower energy and is more stable than a linear polypeptide chain.
- The folding of an amino acid linear chain into a protein takes place in the following way:
- The folding of the amino acid sequence begins during the process of translation of the mRNA (messenger Ribonucleic Acid) by Ribosome. (Co-translational folding)
- This is because initially the linear amino acid sequence forms a secondary structure (alpha helix, beta sheet) which is formed between the nearby amino acid residues.
- These structures form progressively and sequentially and each structure after formation is checked for its correct conformation before the next structure (tertiary structure) is formed.
- If an incorrect folding has occurred, the folded polypeptide chain opens up and refolds until correct orientation is attained.
- Folding, opening and refolding process continues until the correct conformation of the protein is attained.
Answer:
3. haploid; diploid
Explanation:
Sperm is male gamete or often called male reproductive cell. During the process of spermatogenesis, reductional division (meiosis) occurs in the spermatocytes and spermatids are formed which further mature to sperms. Thus as a result of meiosis, their chromosome number is reduced to half and thus they become haploid cells. During oogensis, eggs are also formed as a result of meiosis which reduces the chromosome number and so eggs are also haploid.
When during fertilization, these two haploid nucleus of these cells fuse together, they form a diploid zygote.
