What is imino acid?

Important Questions on Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

In a protein molecule various amino acids are linked together by:

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Protein is very essential for the growth, development and maintenance of living systems. Proteins are natural polymer of $\mathrm{\alpha }-$amino acids. A definite sequence of amino acids form a specific protein. Two or more than two amino acids bind to give peptide bond. Proteins are polypeptide, which loses its biological activity by physical or chemical changes.
Explain essential and non-essential amino acid with example.
 

HARD

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Three given polypeptides $(\mathrm{P},\mathrm{Q}$ and $\mathrm{R})$, of same size and same $\mathrm{pI}(7.2)$, have a single aspartic acid in each of them. In polypeptide $\mathrm{P}$, the aspartic acid residue is on the surface. In polypeptide $\mathrm{Q}$, it is surrounded by negatively charged residues, whereas in polypeptide $\mathrm{R}$ it is deeply buried in a hydrophobic core. $\mathrm{pKa}$ of the side chain carboxylate of free (in solution) aspartic acid is $3.65$. The polypeptides are in a buffer of $\mathrm{pH}$ $7.4$. The change in $\mathrm{pKa}$ of the aspartic acid side chain carboxylate in the polypeptides $\mathrm{P}, \mathrm{Q}$ and $\mathrm{R}$ is likely to

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Which of the following amino acids is NOT involved in gluconeogenesis?

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Choose the CORRECT combination of statements given below related to cysteine residue in proteins.

i. Cysteine can be linked to tyrosine by S-O bond.

ii. Cysteine can be linked to another cysteine by S-S bond.

iii. Cysteine can complex with ${\mathrm{Z}\mathrm{n}}^{2+}.$

iv. Cysteine can be linked to methionine by S-S bond

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

How many different proteins consisting of 100 amino acids can be formed from 20 different amino acids?

HARD

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

A small viral peptide can insert its $6$ amino acids (represented as a barrel) into the lipid bilayer as depicted in the figure given below.

The table depicts the different properties of amino acids.

	Properties
	Polar and uncharged	Polar and charged	Non-polar and hydrophobic
Amino acids	Gly	Asp	Ala
	Ser	Glu	Val
	Thr	Lys	Leu
	Cys	Arg	Ile
	Asn	His	Pro
	Gln	-	Met
	Tyr	-	Phe
	-	-	Trp

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

A $25000 \mathrm{Da}$ protein contains a single binding site for a molecule (ligand), whose molecular weight is $2500 \mathrm{Da}$. Assuming high affinity and physiologically irreversible binding the amount of the ligand required to occupy all the binding sites in $10 \mathrm{mg}$ protein will be:

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Which one of the pairs of amino acids contains two chiral centres?

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Which one of the following amino acids is least likely to be in the core of a protein$?$

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Which of the following is the least likely to be involved in stabilizing the three-dimensional folding of most proteins?

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Identify the statement which is incorrect.

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Which one of the following pairs of molecules never forms a hydrogen bond between them?

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

The Fischer presentation of D-glucose is given below



The correct structure(s) of $\mathrm{\beta }-\mathrm{L}-$ glucopyranose is(are)

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Optical activity of DNA is due to its:

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Phospholipids are formed by the esterification of:

HARD

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

The activity of a certain protein is dependent on its phosphorylation. A mutation in its gene changed a single amino acid which affected the function of the molecule. Which amino acid change is most likely to account for this observation?

MEDIUM

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

If the acidic, basic and hydrophobic residues of proteins are considered to be red, green and blue in colour, respectively, then a globular protein in aqueous solution would have

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Among the following, identify the zwitterionic form

EASY

Life Sciences>From Molecules to Organisms: Structures and Processes>Construct and revise an explanation based on evidence for how carbon, hydrogen, and oxygen from sugar molecules may combine with other elements to form amino acids and/or other large carbon-based molecules.>Organization for Matter and Energy Flow in Organisms - The sugar molecules thus formed contain carbon, hydrogen, and oxygen: their hydrocarbon backbones are used to make amino acids and other carbon-based molecules that can be assembled into larger molecules(such as proteins or DNA), used for example to form new cells.As matter and energy flow through different organizational levels of living systems, chemical elements are recombined in different ways to form different products.

Which one of the following statements is wrong?