Biomolecules Exercise 09

Question:

What is meant by tertiary structure of proteins?

Answer:

Answer:

  1. The tertiary structure of proteins refers to the three-dimensional structure of an individual protein molecule.
  2. It is determined by the sequence of amino acids that make up the protein and the interactions between them, such as hydrogen bonding, van der Waals forces, and electrostatic interactions.
  3. This structure is responsible for the protein’s function, as it determines how the protein interacts with other molecules and its environment.

Question:

Proteins have primary structure, if you are given a method to know which amino acid is at either of the two termini (ends) of a protein, can you connect this information to purity or homogenesity of a protein?

Answer:

  1. The primary structure of a protein is the sequence of amino acids that make up the protein.

  2. Knowing which amino acids are at the two termini (ends) of a protein can provide information about the protein’s sequence.

  3. The purity or homogeneity of a protein is determined by its sequence, so having information about the amino acids at the two termini can help to determine the purity or homogeneity of the protein.

Question:

Explain the composition of triglyceride?

Answer:

  1. A triglyceride is a type of lipid molecule composed of three fatty acid molecules bound to a glycerol molecule.

  2. Fatty acids are long-chain molecules made up of carbon, hydrogen, and oxygen atoms. The number of carbon atoms in a fatty acid can range from 4 to 36.

  3. The glycerol molecule is a three-carbon molecule that binds to the three fatty acids to form a triglyceride.

  4. Triglycerides are the main component of natural fats and oils and are important sources of energy for the body.

Question:

Attempt titrating an amino acid against a weak base and discover the number of dissociating (ionizable) functional groups in the amino acid.

Answer:

  1. Prepare a solution of the amino acid in water.

  2. Measure the pH of the solution and record the value.

  3. Calculate the amount of weak base needed to titrate the solution.

  4. Slowly add the weak base to the amino acid solution, stirring continuously.

  5. Measure the pH of the solution at regular intervals and record the values.

  6. Plot the pH values against the amount of weak base added.

  7. Count the number of points on the graph where the pH changes significantly.

  8. The number of points where the pH changes significantly is equal to the number of dissociating functional groups in the amino acid.

Question:

Draw the structure of the amino acid, Alanine.

Answer:

  1. Alanine is a non-polar, aliphatic amino acid with the chemical formula C3H7NO2.

  2. Draw the carbon backbone of the amino acid, which consists of three carbons (C) connected by single bonds.

C-C-C

  1. Draw the nitrogen (N) and oxygen (O) atoms connected to the carbons.

C-N-C-C-O

  1. Draw the hydrogen (H) atoms connected to the nitrogen and oxygen atoms.

C-N-H-C-H-H-C-O-H

Question:

Can you describe what happens when milk is converted to curd or yoghurt from your understanding of proteins ?

Answer:

  1. Milk contains proteins in the form of casein, which is a type of protein.

  2. When milk is converted to curd or yogurt, the casein proteins are denatured by the action of lactic acid bacteria.

  3. This denaturation causes the proteins to unfold, and the lactic acid bacteria then break down the unfolded proteins into peptides and amino acids.

  4. These peptides and amino acids give the curd or yogurt its characteristic flavor and texture.

Question:

Can you attempt building models of biomolecules using commercially available atomic models (Ball and Stick models).

Answer:

  1. Research the types of commercially available atomic models (Ball and Stick models).

  2. Gather the necessary materials, such as the atomic models, glue, and other supplies.

  3. Read any instructions that come with the atomic models to understand how to assemble them.

  4. Begin assembling the atomic models according to the instructions.

  5. Use the glue to connect the atoms together to form the biomolecule model.

  6. Once the model is complete, review the structure to make sure it accurately portrays the biomolecule.

  7. Make any necessary adjustments to the model to ensure accuracy.

  8. Display the model or use it for further experimentation.

Question:

Find out a qualitative test for proteins, fats and oils, amino acids. Test any fruit juice, saliva, sweat and urine for them.

Answer:

Proteins

  1. Biuret Test: Mix the sample with a few drops of sodium hydroxide solution and a few drops of copper sulfate solution. The formation of a violet color indicates the presence of proteins.

Fats and Oils

  1. Emulsion Test: Mix the sample with equal parts of alcohol and water. If a milky emulsion is formed, it indicates the presence of fats and oils.

Amino Acids

  1. Ninhydrin Test: Mix the sample with ninhydrin solution and heat it. The formation of a purple color indicates the presence of amino acids.

Fruit Juice

  1. Biuret Test: Mix the sample with a few drops of sodium hydroxide solution and a few drops of copper sulfate solution. The formation of a violet color indicates the presence of proteins.
  2. Emulsion Test: Mix the sample with equal parts of alcohol and water. If a milky emulsion is formed, it indicates the presence of fats and oils.
  3. Ninhydrin Test: Mix the sample with ninhydrin solution and heat it. The formation of a purple color indicates the presence of amino acids.

Saliva

  1. Biuret Test: Mix the sample with a few drops of sodium hydroxide solution and a few drops of copper sulfate solution. The formation of a violet color indicates the presence of proteins.
  2. Emulsion Test: Mix the sample with equal parts of alcohol and water. If a milky emulsion is formed, it indicates the presence of fats and oils.
  3. Ninhydrin Test: Mix the sample with ninhydrin solution and heat it. The formation of a purple color indicates the presence of amino acids.

Sweat

  1. Biuret Test: Mix the sample with a few drops of sodium hydroxide solution and a few drops of copper sulfate solution. The formation of a violet color indicates the presence of proteins.
  2. Emulsion Test: Mix the sample with equal parts of alcohol and water. If a milky emulsion is formed, it indicates the presence of fats and oils.
  3. Ninhydrin Test: Mix the sample with ninhydrin solution and heat it. The formation of a purple color indicates the presence of amino acids.

Urine

  1. Biuret Test: Mix the sample with a few drops of sodium hydroxide solution and a few drops of copper sulfate solution. The formation of a violet color indicates the presence of proteins.
  2. Emulsion Test: Mix the sample with equal parts of alcohol and water. If a milky emulsion is formed, it indicates the presence of fats and oils.
  3. Ninhydrin Test: Mix the sample with ninhydrin solution and heat it. The formation of a purple color indicates the presence of amino acids.

Question:

What are gums made of? Is Fevicol different?

Answer:

  1. Gums are usually made of natural gum base or synthetic gum base, which is combined with other ingredients such as sweeteners, softeners, and flavors.

  2. Fevicol is a brand of adhesive, not a gum.

Question:

Find out how much cellulose is made by all the plants in the biosphere and compare it with how much of paper is manufactured by man and hence what is the consumption of plant material by man annually ?

Answer:

Step 1: Research the amount of cellulose produced by plants in the biosphere.

Step 2: Research the amount of paper manufactured by man annually.

Step 3: Compare the amount of cellulose produced by plants in the biosphere with the amount of paper manufactured by man annually.

Step 4: Calculate the amount of plant material consumed by man annually based on the comparison.

Question:

Find out and make a list of proteins used as therapeutic agents. Find other applications of proteins (e.g., cosmetics, etc.)

Answer:

  1. Research proteins used as therapeutic agents. Make a list of the proteins.

  2. Research other applications of proteins. Make a list of the applications. Examples may include cosmetics, food additives, and biofuel production.

Question:

Describe the important properties of enzymes?

Answer:

  1. Enzymes are proteins that act as catalysts to speed up biochemical reactions.
  2. They lower the activation energy of a reaction, making it easier for the reaction to take place.
  3. Enzymes are highly specific, meaning they will only catalyze one particular reaction or a small group of closely related reactions.
  4. Enzymes are not consumed in the reactions they catalyze, but can be used over and over again.
  5. Enzymes work best at certain temperatures and pH levels, and can be denatured or inactivated if the conditions are not optimal.

Question:

Proteins have primary structure. If you are given a method to know which amino acid is at either of the two termini (ends) of a protein, can you connect this information to purity or homogeneity of a protein?

Answer:

  1. Proteins have a primary structure, which is composed of amino acids linked together in a certain sequence.

  2. Knowing which amino acid is at either of the two termini (ends) of a protein can help us to determine the sequence of amino acids in the protein.

  3. This information can be used to assess the purity or homogeneity of a protein, as it allows us to compare the actual sequence of amino acids in the protein to the expected sequence.

  4. If the actual and expected sequences are the same, then the protein is likely to be pure and homogeneous. However, if the actual and expected sequences are different, then the protein is likely to be impure and heterogeneous.

Question:

What are macromolecules? Give examples of it.

Answer:

  1. Macromolecules are large molecules composed of smaller molecules or atoms held together by chemical bonds.

  2. Examples of macromolecules include carbohydrates, proteins, lipids, and nucleic acids. Carbohydrates are composed of carbon, hydrogen, and oxygen atoms and are used for energy storage and structural support. Proteins are composed of amino acids and are important for structure, enzymatic activity, and cell signaling. Lipids are composed of fatty acids and glycerol and are used as energy storage and structural components of cell membranes. Nucleic acids are composed of nucleotides and are responsible for storing and transmitting genetic information.

Question:

Illustrate a glycosidic, peptide and a phosphodiester bond.

Answer:

Glycosidic Bond:

A glycosidic bond is a covalent bond formed between two monosaccharides. It is formed when the hydroxyl group of one monosaccharide reacts with the anomeric carbon of the other monosaccharide. The bond can be represented as a dashed line, with the anomeric carbon of the second monosaccharide being represented by an arrow pointing towards the hydroxyl group of the first monosaccharide.

Peptide Bond:

A peptide bond is a covalent bond between two amino acids. It is formed when the carboxyl group of one amino acid reacts with the amino group of the other amino acid. The bond can be represented as a dashed line, with the carboxyl group of the first amino acid being represented by an arrow pointing towards the amino group of the second amino acid.

Phosphodiester Bond:

A phosphodiester bond is a covalent bond between two nucleotides. It is formed when the phosphate group of one nucleotide reacts with the hydroxyl group of the other nucleotide. The bond can be represented as a dashed line, with the phosphate group of the first nucleotide being represented by an arrow pointing towards the hydroxyl group of the second nucleotide.