Proteins are chains of amino acids. There are twenty different types of naturally occurring amino acids,...

Proteins are chains of amino acids. There are twenty different types of naturally occurring amino acids, and all organisms must have all twenty of them in order to survive. In this project we will be discussing the amino acid leucine. What are the two possible methods that a cell may employ to be certain that it has each of the 20 amino acids?

RNA is partly made of the base uracil. What are the two possible methods that a cell may employ to be certain that it has uracil?

Suppose that you have a particular S. cerevisiae mutant strain that cannot make the amino acid leucine. Will the strain grow on a YPD plate? What about a SD plate? How could you modify the SD plate to allow this strain to grow

Solutions

Expert Solution

1. There are various methods by which cell can ensure that it has all the 20 amino acids they are-

a. The amino acid (essential amino acids-eg- histidine, isoleucine, leucine, tryptophan, threonine, valine, lysine, phenlyalanine and methionine) can be obtained from food by digestion of the proteins present in the food.

b. The cells are capable of synthesizing some amino acids on its own.These aminoacds are also called non-essential amino acids

c. The cell can also utilize the mis-match repair mechanism along with the proof-reading activity of the DNA polymerase to ensure that there is no mistake in the DNA and eventually in the protein coded by the mRNA.

2. To ensure that the cell has uracil 2 methods can be employed

a. Release of enzyme Uracil DNA-glycosylae will remove the uracil if present .

b. The cell can promote cytosine deamination which leads to the formation of uracil.

3. Yes the strain will grow on YPD medium because it is a complete medium for the growth of yeast that has yeast extract, peptone, double-distilled water, and glucose. It also contains all the amino acids essential for the growth of the yeast. On the other hand SD medium is composed of yeast nitrogen base without amino acids and glucose.Therefore the strain will not be able to grow as it cannot make leucine on its own. For the growth of the auxotrophic strain in SD medium the amino acid leucine can be added which will support the growth.

gladiator answered 1 year ago

Next > < Previous

Related Solutions

Common proteins are polymers of 20 different amino acids. How many amino acids are necessary for...

Common proteins are polymers of 20 different amino acids. How many amino acids are necessary for a protein polymer to have at least as many possible different sequences as there are atoms in the Universe? (There are about 2 × 1056 moles of atoms in the Universe.) *Note - The answer is a mathmatical answer. I need an explanation of the math behind this problem.

The 21st and 22nd amino acids found in proteins are the rare amino acids ______________ and...

The 21st and 22nd amino acids found in proteins are the rare amino acids ______________ and ______________. ________________ are nonviral genetic elements that have reverse transcriptase activity. An example of retrotransposons in the human genome is the ____ family of sequences.

Is it possible for naturally produced proteins to have different functions without any change in amino...

Is it possible for naturally produced proteins to have different functions without any change in amino acid sequence or nucleotide sequence? How?

What is false? Proteins are made of long strings of 20 different common amino acids in...

What is false? Proteins are made of long strings of 20 different common amino acids in different orders. The chemical properties of each amino acid are determined by the amino acid's side chain. The order of amino acids in a polypeptide determines the three-dimensional shape of the folded molecule. Most proteins consist of two amino acid polymers attached together by hydrogen bonding.

Proteins are ______________ built from amino acids, which each have an amino group

Proteins are ______________ built from amino acids, which each have an amino group and a _____________ group attached to the central _______________. There are twenty possible _______________ that differ in structure and are generally referred to as “R.” In solutions of neutral pH, amino acids are _______________, carrying both a positive and negative charge. When a protein is made, amino acids are linked together through _______________, which are formed by condensation reactions between the carboxyl end of the last amino...

What amino acids have polar side chains that are attracted to water

Every biochemistry student knows that most naturally occurring unsaturated fatty acids are "cis" fatty acids. Why...

Every biochemistry student knows that most naturally occurring unsaturated fatty acids are "cis" fatty acids. Why then do so many fat-containing foods come with the notation "contains no trans fats"? A) Vegetable oils contain polyunsaturated fatty acids prone to oxidation, which then convert them to trans fats. B) Olive oils, normally healthy oils, are converted to trans fat when cooked at high temperatures. Thus, olive oils are used only at low temperatures. C) Vegetable oils are often hydrogenated to form...

25. If proteins were composed of only 12 different kinds of amino acids, what would be the smallest

25. If proteins were composed of only 12 different kinds of amino acids, what would be the smallest possible codon size in a genetic system with four different nucleotides? A) 1 B) 2 C) 3 D) 4 E) 12 26. From the following list, which is the first event in translation in eukaryotes? A) elongation of the polypeptide B) base pairing of activated methionine-tRNA to AUG of the messenger C) binding of the larger ribosomal subunit to smaller ribosome subunits D) covalent bonding between the first two amino acids E) Both B...

protein molecules are polypetide chains are made up of amino acids in their phisologically functoning or...

protein molecules are polypetide chains are made up of amino acids in their phisologically functoning or native state these chains fold in a unique manner such that the nonpolar groups of the amino acids are usually burired in the interior region of the proteins where there is little or no contact with water. when a protein denatures the chain unfolds so that these non polar groups are exposed to water. a useful estimate of the changes of the thermodynamic quantities...

protein molecules are polypetide chains are made up of amino acids in their phisologically functoning or...

Subjects