Answer:
The correct match for the terms with their description is given below:
Explanation:
- Gene: f) A sequence of nucleotides in DNA that codes for a functional product such as a protein.
- Nucleotide: d) The building blocks of nucleic acids, includes a phosphate, sugar and organic base.
- Chromosome: e) The structure that carries the DNA sequences
- Frameshift mutation a) The loss or addition of a nucleotide pair in a DNA strand.
- Point mutation: c) The substitution of one nucleotide pair for another in DNA strand.
- Genotype: g) The entire genetic makeup of an organism
- Phenotype: b) The physical and biochemical expression of the genotype.
Answer: feed-back
When the product of a metabolic pathway accumulates, it may be able to slow down or turn off the pathway by inhibiting the activity of an enzyme that catalyzes an early step in the pathway. This is referred to as feed-back inhibition.
Explanation:
Feed-back inhibition is said to occur when the final product of a biochemical pathway signal the inactivation of the starting materials of the pathway.
For example: when pyruvate signal the inactivation of phosphofructokinase, the glycolytic pathway gets turned off.
Answer: zap70, ITAM.
Explanation:
An antigen is any substance that is capable of stimulating an immune response by activating lymphocytes, which are the body’s infection-fighting white blood cells. Examples of antigens could be proteins that are part of bacteria or viruses or components of serum and red blood cells from other individuals, all of them are foreign antigens originated outside the body. However, there can also be autoantigens (which are self-antigens), originated within the body. In normal conditions, the body is able to distinguish self from nonself. <u>And the antigens that represent a danger induces an immune response by stimulating the lymphocytes to produce antibody or to attack the antigen directly</u>. This is called an antigenic stimulation of the immune system.
ZAP-70 (Zeta-chain-associated protein kinase 70) is a protein that is part of the T cell receptor, thereby it plays a critical role in T-cell signaling. When the TCR (receptor of T cells) is activated by the presentation of the specific antigen through the MHC, a protein called Lck acts to phosphorylate the intracellular CD3 chains and the ζ chains of the TCR complex, allowing the binding of the cytoplasmic tyrosine kinase, ZAP-70. Lck then phosphorylates and activates ZAP-70, which in turn phosphorylates another molecule in the signaling cascade called LAT (short for Linker of Activated T cells), a transmembrane protein that serves as an anchor site for several other proteins. The tyrosine phosphorylation cascade initiated by the Lck culminates in the intracellular mobilization of calcium ion (Ca2+) <u>and the activation of important signaling cascades within the lymphocytes.</u> These include the Ras-MEK-ERK pathway, which is based on activating certain transcription factors such as NFAT, NFκB and AP-1. These transcription factors regulate the production of of certain gene products, most notably cytokines such as interleukin-2 that promote the long-term proliferation and differentiation of activated lymphocytes.
The ITAM motifs (immunoreceptor tyrosine-based activation motif) are sequences of four amino acids present in the intracellular tails of certain proteins that serve as receptors within the immune system. Thus, <u>some receptors such as the TCR have ITAM sequences that, when activated, trigger an intracellular reaction based on consecutive phosphorylations</u>. Kinases are recruited for this purpose.
So, ZAP-70 is a protein tyrosine kinase with a role in T-cell receptor signal transduction. During T-cell activation, ZAP-70 binds to ITAM and becomes tyrosine phosphorylated. The binding of ZAP-70 to the phosphorylated ITAM is able to activate its kinase activity, <u>and relieves the inhibition of the transcription factor which regulates genes that are involved in the immune reaction</u>.
Potassium, carbon, sulfur, hydrogen, oxygen, nitrogen, calcium, magnesium, sodium, phosphorus, iron, zinc, silicon, fluorine, boron, cobalt, manganese, chromium, and some others
<span>Plants, animals, and humans all need </span>shelter<span> to survive. Plants in ... When an area has many different species living in the same habitat, it has a </span>great<span> deal of biodiversity. ... Just about every other plant on earth </span>would<span> wilt and die if it were exposed to the ... The ground of the </span>rainforest<span> is called the </span>forest<span> floor.</span>
