Answer:
Proteins and lipids exist as separate but loosely attached molecules that can move around
Explanation:
Cell membranes are mainly composed of lipids, proteins, and also carbohydrates. Phospholipids are the most abundant type of lipid and the main constituent of the cell membranes. Membrane proteins are divided into two types according to their interactions with the cell membrane: 1-integral (intrinsic) and peripheral (extrinsic) proteins. These peripheral proteins are loosely attached by ionic bonds or calcium bridges with the phosphate heads of the phospholipids; whereas integral membrane proteins contain side chains that interact with fatty acyl groups of the phospholipids. Cell membrane fluidity indicates how easily lipids (e.g., phospholipids and cholesterol) and proteins (e.g., intrinsic proteins) diffuse laterally in the cell membrane. This fluidity is affected by the amount of cholesterol, temperature, and the ratio of unsaturated to saturated fatty acids. Saturated fatty acids have no double bonds in the hydrocarbon chain, whereas unsaturated fatty acids have at least one double bond (these double bonds increase fluidity). Moreover, higher temperatures increase membrane fluidity, whereas cholesterol molecules function to regulate membrane fluidity: at high temperatures cholesterol molecules stabilize the membrane, whereas at low temperatures intercalate between phospholipids, thereby preventing them from clustering together.
The process by which DNA is copied to RNA is called transcription, and that by which RNA is used to produce proteins is called translation.
The right answer is B.
Cholera vaccination is only recommended for staff who have to intervene with patients in an epidemic situation. In all other cases, effective prevention is provided by good personal hygiene (washing hands) and food.
It is also important to know that this vaccine does not protect permanently: It protects only about 90% within 6 months, then to 50% within 3 years.
Answer:
The correct answer is: Variation in nucleotide sequences are located in those regions of the gene which do not affect the sequence of the protein due to genetic code degeneracy.
Explanation:
- Proteins are encoded from the genes located in the chromosomes.
- The genes are made up of the heritable DNA (Deoxyribonucleic Acid) sequences.
- These genes are transcribed by the enzyme called RNA polymerase into mRNA (messenger Ribonucleic Acid) sequences in the nucleus.
- The mRNA is then translated into protein sequences by the Ribosome in the cytoplasm or the RER (Rough Endoplasmic Reticulum).
- The Ribosome reads the mRNA code in form of triplets, that is, three consecutive nucleotide are read as a single code that encode for a single amino acid. This triplet code that responsible for coding for a single amino acid is called a Codon.
- The Codons are degenerate in nature. This means that among the three nucleotide in a codon the first two nucleotide is specific for a particular amino acid. The third nucleotide is "wobble" in nature. This means that whatever may be the nucleotide in the third position it will not change the amino acid coded by the first two nucleotide.
- Hence, a single amino acid is coded by more than one codon.
- So, gene sequences showing variation in the wobble nucleotide position will encode for the same protein.
Axon, dendrite
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