Answer:
Cell serves as the basic building blocks for building the structure or the body of the living organisms. Now, certain type or specific number of cells come closer and arrange themselves in such a sequence that they need to perform a unique or specific task by making up a whole organ structure.
Explanation:
There are certain cells inside the human body which makes up a single organ and then performs the whole function specifically by themselves, as we have the "myocardial myocytes". These are the specific type of cells which are required for the heart's cardiac muscles to develop or grow in a given pattern. As these cells are specialized for making up or building up of the cardiac muscles which in turns results in the heart structure. And performs the basic function of supply of blood and the required materials i.e nutrients to the different cells and organs.
Answer:
False, it is only represented by one class: Crinoidea (sea lilies).
Explanation:
Echinoderms (phylum Echinodermata) are marine organisms that comprises more than 6,000 species. These animals are deuterostomes that are differentiated to have an ambulacral vascular system and a pentameric symmetry. Echinoderms are divided in the following classes: 1- Ophiuroidea (snake stars), 2-Asteroidea (sea stars), 3-Crinoidea (sea lilies), 4-Holothuroidea (sea cucumbers) and 5-Echinoidea (sea urchins), which can be easily distinguished by anatomical and ecological characteristics.
Answer:
Simplified diagram of pyruvate oxidation. Pyruvate—three carbons—is converted to acetyl CoA, a two-carbon molecule attached to coenzyme A. A molecule of coenzyme A is a necessary reactant for this reaction, which releases a molecule of carbon dioxide and reduces a NAD+ to NADH.
Simplified diagram of pyruvate oxidation. Pyruvate—three carbons—is converted to acetyl CoA, a two-carbon molecule attached to coenzyme A. A molecule of coenzyme A is a necessary reactant for this reaction, which releases a molecule of carbon dioxide and reduces a NAD+ to NADH.
In eukaryotes, this step takes place in the matrix, the innermost compartment of mitochondria. In prokaryotes, it happens in the cytoplasm. Overall, pyruvate oxidation converts pyruvate—a three-carbon molecule—into acetyl two-carbon molecule attached to Coenzyme A—producing an t, N, A, D, H, end text and releasing one carbon dioxide molecule in the process. Acetyl C, o, A, end text acts as fuel for the citric acid cycle in the next stage of cellular respiration.
Pyruvate oxidation steps
Pyruvate is produced by glycolysis in the cytoplasm, but pyruvate oxidation takes place in the mitochondrial matrix (in eukaryotes). So, before the chemical reactions can begin, pyruvate must enter the mitochondrion, crossing its inner membrane and arriving at the matrix.
In the matrix, pyruvate is modified in a series of steps:
More detailed diagram of the mechanism of pyruvate oxidation.
1. A carboxyl group is removed from pyruvate and released as carbon dioxide.
2. The two-carbon molecule from the first step is oxidized, and NAD+ accepts the electrons to form NADH.
3. The oxidized two-carbon molecule, an acetyl group, is attached to Coenzyme A to form acetyl CoA.
More detailed diagram of the mechanism of pyruvate oxidation.
A carboxyl group is removed from pyruvate and released as carbon dioxide.
The two-carbon molecule from the first step is oxidized, and NAD+ accepts the electrons to form NADH.
The oxidized two-carbon molecule, an acetyl group, is attached to Coenzyme A to form acetyl CoA.
Image credit: "Oxidation of pyruvate and the citric acid cycle: Figure 1" by OpenStax College, Biology, CC BY 3.0
Step 1. A carboxyl group is snipped off of pyruvate and released as a molecule of carbon dioxide, leaving behind a two-carbon molecule.
Step 2. The two-carbon molecule from step 1 is oxidized, and the electrons lost in the oxidation are picked up 2 \text{NADH}NADHstart text, N, A, D, H, end text are generated from \text{NAD}^+NAD
Step 3. The oxidized two-carbon molecule—an acetyl group, highlighted in green—is attached to Coenzyme A (\text{CoA}CoAstart text, C, o, A, end text), an organic molecule derived from vitamin B5, to form acetyl \text{CoA}CoAstart text, C, o, A, end text. Acetyl \text{CoA}CoAstart text, C, o, A, end text is sometimes called a carrier molecule, and its job here is to carry the acetyl group to the citric acid cycle.
The steps above are carried out by a large enzyme complex called the pyruvate dehydrogenase complex, which consists of three interconnected enzymes and includes over 60 subunits. At a couple of stages, the reaction intermediates actually form covalent bonds to the enzyme complex—or, more specifically, to its cofactors. The pyruvate dehydrogenase complex is an important target for regulation, as it controls the amount of acetyl \text{CoA}CoAstart text, C, o, A, end text fed into the citric acid cycle^{1,2,3}
1,2,3
start superscript, 1, comma, 2, comma, 3, end superscript.
If we consider the two pyruvates that enter from glycolysis (for each glucose molecule), we can summarize pyruvate oxidation as follows:
Two molecules of pyruvate are converted into two molecules of acetyl \text{CoA}CoAstart text, C, o, A, end text.
Two carbons are released as carbon dioxide—out of the six originally present in glucose.
2 \text{NADH}NADHstart text, N, A, D, H, end text are generated from \text{NAD}^+NAD
+
start text, N, A, D, end text, start superscript, plus, end superscript.
Why make acetyl \text{CoA}CoAstart text, C, o, A, end text? Acetyl \text{CoA}CoAstart text, C, o, A, end text serves as fuel for the citric acid cycle in the next stage of cellular respiration. The addition of \text{CoA}CoAstart text, C, o, A, end text helps activate the acetyl group, preparing it to undergo the necessary reactions to enter the citric acid cycle.
Explanation:
Answer:Amino acids, often referred to as the building blocks of proteins, are compounds that play many critical roles in your body. They're needed for vital processes like the building of proteins and synthesis of hormones and neurotransmitters.
Explanation:
b. gene expression
c. an operon
d. induction
Answer:
d. induction
Explanation:
A repressor is a protein capable of inhibiting target gene expression by binding to both operator sites and gene silencers. A DNA-binding repressor inhibits the interaction between the RNA polymerase and the DNA promoter sequence, thereby suppressing transcription into RNA. Moreover, the RNA-binding repressor is a protein that binds to the messenger RNA (mRNA) molecule in order to prevent its translation into protein. An inducer can start transcription by interacting with the repressor, thereby separating it from the DNA operator sequence.
Answer:
There will be no movement of kinesin motor protein along the microtubules .
Explanation:
Microtubules is an important component of cytoskeleton which play an important role in maintaining cell shape,cell motility,cell division regulation etc.
Whereas kinesin belongs to the family of motor proteins present in the eukaryotic cell.Kinesin plays an important role axonal transport.
The hydrolysis of ATP generates energy to power up the movement of kinesin along the microtubules.
According to the given question if kinesin and microtubules were incubated with an non hydrolyzable ATP analog instead of ATP,then the movement of kinesin along the microtubules will not occur due to lack of energy because the non-hydrolyzable analog of ATP cannot undergo hydrolysis to release energy.