Answer:
A nucleotide is composed of three components: a nitrogenous base, a sugar molecule, and a phosphate group.
Explanation:
1. Nitrogenous Base: There are two types of nitrogenous bases found in nucleotides: purines and pyrimidines. Purines include adenine (A) and guanine (G), while pyrimidines include cytosine (C), thymine (T), and uracil (U) in RNA. These nitrogenous bases have different pKa values: adenine and guanine have pKa values around 3.5, while cytosine, thymine, and uracil have pKa values around 4.5.
2. Sugar Molecule: The sugar molecule in a nucleotide is either deoxyribose (in DNA) or ribose (in RNA). Deoxyribose and ribose are both five-carbon sugars. Deoxyribose has a hydrogen atom at the 2' carbon position, while ribose has a hydroxyl group (OH) at the same position. The pKa of the sugar molecule is not relevant to the connection between nucleotides.
3. Phosphate Group: The phosphate group consists of a phosphorus atom bonded to four oxygen atoms. One oxygen is connected to the 5' carbon of the sugar molecule, forming a phosphodiester bond. The pKa of the phosphate group is around 1.
The three components of a nucleotide connect to each other through covalent bonds. The nitrogenous base is connected to the 1' carbon of the sugar molecule, forming a glycosidic bond. The phosphate group is connected to the 5' carbon of the sugar molecule through a phosphodiester bond. This connection repeats in a linear fashion, forming a chain of nucleotides. In DNA, this chain forms the double helix structure through hydrogen bonding between complementary nitrogenous bases (A with T and G with C), while in RNA, the chain remains single-stranded.
To summarize, the three components of a nucleotide are the nitrogenous base, the sugar molecule, and the phosphate group. The relevant pKa values are around 3.5 for adenine and guanine, around 4.5 for cytosine, thymine, and uracil, and around 1 for the phosphate group. These components connect to each other through glycosidic bonds between the base and the sugar, and phosphodiester bonds between the sugar and the phosphate group.
b. scientific
c. 4
d. social
scientific !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
b. exoskeleton
c. labium
d. ocelli
B) chlorophyll.
C) cytochrome a.
D) cytochrome c.
Answer:
The correct answer is cephalization.
Explanation:
Being a evolutionary feat, cephalization is umbrella term for concentration of sense organs such as eyes and ears, feeding organs such as mouth and nervous system such as ganglia, brain and cerebellum. For flatworms the ganglia concentrated in one end of the body which is "nerve tissue" in your question.
Answer:
Metaphase
Explanation:
During metaphase, parts of the spindle extend and the chromosomes align at the middle part of the cell. Notice that each chromosome consists of two identical strands held together at a point in the middle.
-Therefore, metaphase is the second stage of mitosis