what is the job of a ribosome?

Question

a) to match anticodons to codons
b) match the amion acids to the tRNA
c) to make tRNA

Answer 1

i guess a, but that doesnt tell the whole story at all.

Answer 2

The ribosomal subunits of prokaryotes and eukaryotes are quite similar. However, prokaryotes have 70S ribosomes, each consisting of a (small) 30S and a (large) 50S subunit, whereas eukaryotes have 80S ribosomes, each consisting of a (small) 40S and a bound (large) 60S subunit. However, the ribosomes found in chloroplasts and mitochondria of eukaryotes are 55S. The unit "S" means Svedberg units, a measure of the rate of sedimentation of a particle in a centrifuge, where the sedimentation rate is associated with the size of the particle. It is important to note that Svedberg units are not addable - two subunits together can have Svedberg values that do not add up to that of the entire ribosome. This is resulting from the loss of surface area when the two subunits are bound. In addition, the ungainly shape of the fully assembled ribosome has different aqua dynamic properties from the two unbound subunits. The differences between the prokaryotic and eukaryotic ribosomes are exploited by humans since the 70S ribosomes are vulnerable to some antibiotics that the 80S ribosomes are not. This helps create drugs that can destroy a bacterial infection without harming the animal/human host's cells. Even though human mitochondria possess 55S ribosomes with rRNA compounds similar to bacterial ribosomes, mitochondria are rarely affected by these antibiotics because mitochondria are covered by a double membrane that does not easily admit these antibiotics into the organelle.



Ribosomes are the workhorses of protein synthesis, the process of translating messenger RNA (mRNA) into protein. The mRNA comprises a series of codons that dictate to the ribosome the amino acids needed to make the protein. Using the mRNA as a template, the ribosome traverses each codon of the mRNA, pairing it with the appropriate amino acid. This is done using molecules of transfer RNA (tRNA) containing a complementary anticodon on one end and the appropriate amino acid on the other.



Protein synthesis begins at a start codon near the 5' end of the mRNA. The small ribosomal subunit, typically bound to a tRNA containing the amino acid methionine, binds to an AUG codon on the mRNA and recruits the large ribosomal subunit. The large ribosomal subunit contains three tRNA binding sites, designated A, P, and E. The A site binds an aminoacyl-tRNA (a tRNA bound to an amino acid); the P site binds a peptidyl-tRNA (a tRNA bound to the peptide being synthesized); and the E site binds a free tRNA before it exits the ribosome.



You could get more information from the link below...

Answer 3

The Genetic Code

The job of the ribosome is to build a protein from the ingredient list brought ... The ribosome assembles the twenty kinds of amino acids into a chain as ...members.tripod.com/c_rader0/gcode.htm

Answer 4

is a suite of build tools, written mainly in Python, which provide a common interface to retrieving and building programs from source code stored in a CVS repository. All Helix products are built using the Ribosome tools.

Ribosome is composed of two main tools and several helper tools:

Main Tools:

build.py - This tool calculates the dependencies of a target, retrieves the source code, and runs commands to build that source code in the correct order.

umake.py - A cross-platform Makefile generator. umake can be used independently from build to generate Makefiles, but build will call umake during its operation.

Helper Tools:

armerge.py - Merges static libraries into a single library.

gethash.exe - Checks DLL's for drm signing.

mkdepend.py - Generates header dependency information for Makefiles (similar to makedepend).

pyar.py - On POSIX systems, creates libarary archive files.

pylink.py - Links DLLs and intelligently assigns preferred load addresses.

rebase.py - Reassigns base addresses to all the DLL's in a directory subtree. Useful during rebuilds where some DLL's change size but we don't relink everything.

rlink.py - Perform function-level linking on gcc platforms.

sign.py - With proper permissions, requests signing for a file. Internal RN tool only.

testdriver.py - Runs unit tests on a single module

testsuite.py - Runs unit tests on entire project

Answer 5

I'm not sure if this really answers ur question, but I learned that ribosomes produce proteins and are found attached to the endoplasmic reticulum.

To learn more, visit: http://en.wikipedia.org/wiki/Ribosome

Answer 6

Ribosomes (from ribonucleic acid and "Greek: soma (meaning body)") are complexes of RNA and protein that are found in all cells. Ribosomes from bacteria, archaea and eukaryotes, the three domains of life, have significantly different structure and RNA. Interestingly, the ribosomes in the mitochondrion of eukaryotic cells resemble those in bacteria, reflecting the evolutionary origin of this organelle.[1] The ribosome functions in the expression of the genetic code from nucleic acid into protein, in a process called translation. Ribosomes do this by catalyzing the assembly of individual amino acids into polypeptide chains; this involves binding a messenger RNA and then using this as a template to join together the correct sequence of amino acids. This reaction uses adapters called transfer RNA molecules, which read the sequence of the messenger RNA and are attached to the amino acids. Ribosomes are about 20nm (200 Ångström) in diameter and are composed of 65% ribosomal RNA and 35% ribosomal proteins (known as a Ribonucleoprotein or RNP). They translate messenger RNA (mRNA) to build polypeptide chains (e.g., proteins) using amino acids delivered by transfer RNA (tRNA). Their active sites are made of RNA, so ribosomes are now classified as "ribozymes."[2] Ribosomes build proteins from the genetic instructions held within messenger RNA. Free ribosomes are suspended in the cytosol (the semi-fluid portion of the cytoplasm); others are bound to the rough endoplasmic reticulum, giving it the appearance of roughness and thus its name, or to the nuclear envelope. As ribozymes are partly constituted from RNA, it is thought that they might be remnants of the RNA world.[3] Catalysis of the peptide bond involves the C2 hydroxyl of RNA's P-site adenosine in a protein shuttle mechanism. The full function (i.e. translocation) of the ribosome is reliant on changes in protein conformations. Ribosomes are sometimes referred to as organelles, but the use of the term organelle is often used only in reference to sub-cellular components that include a phosholipid membrane, which ribosomes, being entirely particulate, do not. For this reason, ribosomes may sometimes be described as "non-membranous organelles". Ribosomes are an extremely important structure in the cell. Ribosomes were first observed in the mid-1950s by Romanian cell biologist George Palade using an electron microscope as dense particles or granules[4] for which he would win the Nobel Prize. The term "ribosome" was proposed by scientist Richard B. Roberts in 1958 The structure and function of the ribosomes and associated molecules, known as the translational apparatus, has been of research interest since the mid-twentieth century and is a very active field of study today. Figure 2 : Large (1) and small (2) subunit fit togetherRibosomes consist of two subunits (Figure 1) that fit together (Figure 2) and work as one to translate the mRNA into a polypeptide chain during protein synthesis (Figure 3). Bacterial subunits consist of one or two and eukaryotic of one or three very large RNA molecules (known as ribosomal RNA or rRNA) and multiple smaller protein molecules. Crystallographic work has shown that there are no ribosomal proteins close to the reaction site for polypeptide synthesis. This suggests that the protein components of ribosomes act as a scaffold that may enhance the ability of rRNA to synthesize protein rather than directly participating in catalysis In bacterial cells, ribosomes are synthesized in the cytoplasm through the transcription of multiple ribosome gene operons. In eukaryotes and some bacterial cells, the process takes place both in the cell cytoplasm and in the nucleolus of eukaryotic cells. It involves the coordinated function of over 200 proteins in the synthesis and processing of the four rRNAs, as well as assembly of those rRNAs with the ribosomal proteins. Ribosome locations Ribosomes are classified as being either "free" or "membrane-bound." Free ribosomes Free ribosomes are free to move about anywhere in the cytosol. Proteins that are formed from free ribosomes are used within the cell. Proteins containing disulfide bonds using cysteine amino acids cannot be produced outside of the lumen of the endoplasmic reticulum. Membrane-bound ribosomes When certain proteins are synthesized by a ribosome they can become "membrane-bound". The newly produced polypeptide chains are inserted directly into the endoplasmic reticulum by the ribosome and are then transported to their destinations. Bound ribosomes usually produce proteins that are used within the cell membrane or are expelled from the cell via exocytosis. Free and membrane-bound ribosomes differ only in their spatial distribution; they are identical in structure and function. Whether the ribosome exists in a free or membrane-bound state depends on the presence of a ER-targeting signal sequence on the protein being synthesized. Structure

Answer 7

a) to match anticodons to codons

Answer 8

A

Answer 9

A