Answer:
Amino Acids are a type of organic compound that can combine to from proteins. Foods with good Amino Acids include meat, eggs, tofu, soy and dairy. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen.
Answer: RNAs are not processed before translation in prokaryotes, this process only takes place in eukaryotes.
Explanation:
Messenger RNA or mRNA is a single-straded ribonucleic acid that transfers the genetic information from the DNA (deoxyribonucleic acid) molecule of the cell nucleus to a ribosome (which are the machinery responsible for protein synthesis) in the cytoplasm. mRNA determines the order in which the amino acids of a protein will be joined and acts as a template or pattern for the synthesis of that protein. To accomplish this, the DNA molecule must be transcribed into an RNA molecule, which is used for protein synthesis.
The messenger RNA obtained after transcription is known as primary transcribed RNA or precursor RNA or pre-mRNA, which in most cases is not released from the transcription complex in a fully active form, but in eukaryotes it must undergo modifications before it can perform its function (RNA processing or maturation). These modifications include:
- Elimination of fragments (splicing): In most cases, the <u>mRNA undergoes the removal of internal, non-coding sequences called introns, and the connection of exons. This does not occur in prokaryotic cells</u>, as they do not have introns in their DNA.
- Protection by CAP: <u>Addition to the 5' end of the structure called "cap" or "capping"</u>, which is a modified guanine nucleotide, 7-methylguanosine triphosphate, via a 5'-5' triphosphate linkage, instead of the usual 3',5'-phosphodiester linkage. This cap is necessary for the normal RNA translation process and to maintain its stability.
- Polyadenylation signal: <u>Addition to the 3' end of a poly-A tail, a long polyadenylate sequence, whose bases are all adenine</u>. Its addition is mediated by a sequence or polyadenylation signal (AAAAAA), located 11-30 nucleotides upstream of the original 3' end. This tail protects the mRNA from degradation, and increases its half-life in the cytosol, so that more protein can be synthesized.
The mature mRNA (in eukaryotes) is transferred to the cytosol of the cell through pores in the nuclear envelope. Once in the cytoplasm, ribosomes are coupled to the mRNA. However, in prokaryotes, ribosome binding occurs while the mRNA strand is being synthesized. After a certain amount of time, the mRNA is degraded into its component nucleotides by ribonucleases. So, the transcription and translation processes are carried out in a similar way as in eukaryotic cells but they occur simultaneously. But, the fundamental difference is that, in prokaryotes, the messenger RNA does not undergo a maturation process and, therefore, no cap or tail is added and no introns are removed. Moreover, it does not have to leave the nucleus as in eukaryotes, because in prokaryotic cells there is no defined nucleus.
So, RNAs are not processed before translation in prokaryotes, this process only takes place in eukaryotes.
Answer:
The fact that it reveals is that:
Epinephrine binds to the receptor tyrosine kinase on the cell membrane and does not act on glycogen phosphorylase.
Explanation:
In cellular respiration, epinephrine is a neurotransmitter and a plasma membrane hormone receptor. It is not a lipid-derived hormone, but rather an amino acid-derived hormone. As a result, they are unable to pass through the plasma membrane of cells. They bind to receptors on the outer surface of the plasma membrane through plasma membrane hormone receptors (receptor's tyrosine kinase of the cell membrane) because they are lipid insoluble hormones.
Unlike steroid hormones, lipid insoluble hormones (epinephrine) do not directly influence glycogen phosphorylase or the target cell because they cannot enter the cell and operate directly on DNA. The activation of a signaling pathway occurs when these hormones attach to a cell surface receptor; this activates intracellular activity and performs the hormone's specific effects. Nothing crosses through the cell membrane in this fashion; the hormone that binds at the cell's surface stays at the cell's surface, while the intracellular component stays within the cell.
Answer:
Translation occurs in a structure called the ribosome, which is a factory for the synthesis of proteins. ... Translation of an mRNA molecule by the ribosome occurs in three stages: initiation, elongation, and termination. During initiation, the small ribosomal subunit binds to the start of the mRNA sequence.
Explanation:
Answer:
Must have lived before.
Explanation:
For an organism to be classified as once living, an object must have been part of a living organism or is now dead. When a flower is plucked from a plant it is hard to distinguish between when it is considered alive and when it is now considered once living. An example of a nonliving object is an apple or a dead leaf.Apr 22, 2013
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