Algebra Class 10 Quiz

Learning Objectives

• Define proteins with examples
• Classify proteins with examples
• List the sources and properties of proteins
• Describe functions and biomedical importance of proteins

Chemistry of Proteins

• Proteins are complex, high molecular weight, nitrogenous organic compounds.
• The basic unit of a protein molecule is an amino acid.
• The properties of a protein are determined by the R-groups on the amino acids.

Amino Acids

• Amino acids are the subunits of proteins.
• Most commonly, there are 20 different amino acids coded in DNA
• Some bacteria also use 22 amino acids (Selenocysteine and pyrrolysine).
• Amino acid properties differ based on their R-groups.
  • Hydrophobic: Leucine, isoleucine, valine, methionine, phenylalanine, tryptophan
  • Positively charged (basic): lysine, arginine, histidine
  • Negatively charged (acidic): aspartate, glutamate
  • Polar but uncharged: serine, threonine, asparagine, glutamine
  • Chain bending (imino acid): proline
  • Disulfide bridge forming: cysteine
  • Small: glycine, alanine, serine

Essential and Non-Essential Amino Acids

• 10 amino acids are essential, meaning they must be consumed in the diet .
• Examples of essential amino acids include: arginine, histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine.
• Other amino acids are nonessential.

Protein Structure

• Proteins have a primary structure. This is a linear sequence of amino acids linked together by peptide bonds.
• Proteins have a secondary structure that consists of local spatial structures of peptide segments. Hydrogen bonds help stabilize this structure.
• The tertiary structure is the complete three-dimensional arrangement of all atoms in a protein, stabilizing through various interactions like hydrogen, ionic, and hydrophobic interactions. Disulfide bonds also contribute.
• The quaternary structure is the spatial arrangement of multiple subunits in a protein.

Rich Sources of Proteins

• The presentation listed various foods rich in protein, such as various meats, fish, poultry, eggs, dairy, vegetables and legumes.

Physical and Chemical properties

• Proteins are made up of carbon, hydrogen, oxygen, nitrogen and small amounts of sulphur.
• Proteins link amino acids through peptide bonds.
• Protein enzymes catalyze chemical reactions
• Proteins provide structural support for cells
• Proteins transport substances across cell membranes
• Proteins defend against pathogens (e.g. antibodies).
• Proteins secrete hormones
• Proteins are denatured by factors like heat, acids, and bases, causing a change in the protein's structure and function.
• Denaturation often involves precipitation or coagulation of the protein. This is seen in examples like cooking eggs or heating milk.

Classification of Proteins

• Simple proteins consist only of amino acids.

• Conjugated proteins combine with non-protein components (prosthetic groups).

• Derived proteins are degradation products of native proteins.

  -Examples of conjugated proteins include glycoproteins, lipoproteins, nucleoproteins, and chromoproteins. - Glycoproteins contain sugar molecules. - Lipoproteins contain lipid molecules. - Nucleoproteins contain nucleic acids. - Chromoproteins contain pigments (e.g., heme in hemoglobin).

Malnutrition

• Kwashiorkor and Marasmus can arise from protein and calorie deficiencies respectively.

Classification of Proteins by Nutritional Value

• First class proteins contain all essential amino acids in sufficient amounts.
• Second class proteins are missing one essential amino acid.
• Third class proteins lack many essential amino acids.

Colloidal Osmotic Pressure (COP)

• Protein molecules influence blood pressure.
• Plasma proteins, primarily albumins contribute to COP, maintaining blood volume.

Capillary Exchange

• Blood pressure and osmotic pressure determine fluid movement in and out of capillaries.

Hydration of Proteins

• Proteins absorb water, swelling up due to their hydration shells where polar groups interact favorably with surrounding water molecules.

Isoelectric Point (pI)

• pI is the pH at which a protein exists as a zwitter ion (neutral charge).
• Isoelectric point measurements can be used in protein separation and identification.

Precipitation of Proteins by Salts

• Hydrophobic amino acids in proteins cluster together, pushing out water.
• Increasing salt concentration can affect solvation layers and bring proteins together to precipitate.

Structual Shape

• Fibrous proteins have a long, thin shape, often forming fibers.
• Globular proteins are roughly spherical and are usually soluble in water. A variety of functions.

Function of Proteins

• Presentation details various functions of proteins including:
• Enzymes: Catalyzing biochemical reactions
• Hormones: Coordinating bodily functions
• Structural: Supporting bodily structures
• Transport: Moving substances through the body
• Contractile: Muscle movement
• Storage: Storing nutrients within cells
• Receptors: Responding to stimuli
• Protective: Defense against pathogens
• Proteins within blood plasma (e.g., albumin, immunoglobulins).

Test your knowledge on basic algebraic expressions and the application of the distributive property. This quiz includes evaluation of expressions and simplification techniques. Perfect for 10th-grade students looking to reinforce their algebra skills.