Answer:
C) The Calvin cycle requires ATP and NADPH, which require sunlight to be produced
Explanation:
The light-dependent phase of photosynthesis includes the photolysis of water molecules. The released electrons are passed to PSII to PSI via electron carriers and finally to NADP+ to reduce it into NADPH.
Transfer of electrons via electron carriers also generates the proton concentration gradient which in turn drives ATP synthesis. ATP and NADPH formed during light reactions are used in the Calvin cycle as an energy source and electron donor respectively.
Hence, to continue, the Calvin cycle requires the synthesis of ATP and NADPH in the presence of light.
Answer:
A transfer RNA (abbreviated tRNA and formerly referred to as sRNA, for soluble RNA is an adaptor molecule composed of RNA, typically 76 to 90 nucleotides in length,that serves as the physical link between the mRNA and the amino acid sequence of proteins. Transfer RNA does this by carrying an amino acid to the protein synthetic machinery of a cell (ribosome) as directed by the complementary recognition of a 3-nucleotide sequence (codon) in a messenger RNA (mRNA) by a 3-nucleotide sequence (anticodon) of the tRNA. As such, tRNAs are a necessary component of translation, the biological synthesis of new proteins in accordance with the genetic code.
Each mRNA molecule is simultaneously translated by many ribosomes, all reading the mRNA from 5′ to 3′ and synthesizing the polypeptide from the N terminus to the C terminus. The complete mRNA/poly-ribosome structure is called a polysome.
tRNAs in eukaryotes
The tRNA molecules are transcribed by RNA polymerase III. Depending on the species, 40 to 60 types of tRNAs exist in the cytoplasm. Specific tRNAs bind to codons on the mRNA template and add the corresponding amino acid to the polypeptide chain. (More accurately, the growing polypeptide chain is added to each new amino acid bound in by a tRNA.)
The transfer RNAs (tRNAs) are structural RNA molecules. In eukaryotes, tRNA mole are transcribed from tRNA genes by RNA polymerase III. Depending on the species, 40 to 60 types of tRNAs exist in the cytoplasm. Serving as adaptors, specific tRNAs bind to sequences on the mRNA template and add the corresponding amino acid to the polypeptide chain. (More accurately, the growing polypeptide chain is added to each new amino acid brought in by a tRNA.) Therefore, tRNAs are the molecules that actually “translate” the language of RNA into the language of proteins.
An adaptation-----------------------
Answer: the factors that increase cardiac output include:
--> Nervous stimulation and
--> Hypertrophy of the heart.
Explanation:
Cardiac output can be defined as the quantity of blood pumped into the aorta each minute by the heart. This is also the quantity of blood that flows through the circulation. There are factors that can cause increased cardiac output or that can lead to a hypereffective heart. They are:
--> NERVOUS STIMULATION: The combination of sympathetic stimulation and parasympathetic inhibition does two things to increase the pumping effectiveness or cardiac output of the heart. These include:
• it greatly increase the heart rate from the normal level of 72 beats/mum up to 180 to 200 beats /mom.
• it increases the strength of heart contraction, which is called increased contractility to twice it's normal strength.
--> HYPERTROPHY OF THE HEART: A long term increased workload, but not so much excess load that it damages the heart, causes the heart muscle to increase in mass and contractile strength in the same way that heavy exercise causes skeletal muscles to hypertrophy. This effect of increased muscle mass of the heart, allows the heart to pump much greater than usual amounts of cardiac output.