Biology: Biomolecules and Proteins

Study Notes

Organization of Life

Levels of organization: molecules, organelles, cells, tissues, organs, organ systems, organisms

Importance of Water

Water is essential for life, making up approximately 60-70% of an organism's body weight
Water's unique chemical and physical properties allow it to play a crucial role in biological processes

Biomolecules

Amino Acids

Building blocks of proteins
20 standard amino acids, classified as essential or non-essential
Amino acids linked by peptide bonds form a polypeptide chain

Carbohydrates

Provide energy and structural support
Classified as monosaccharides, disaccharides, and polysaccharides
Examples: glucose, fructose, sucrose, lactose, glycogen, starch, cellulose

Lipids

Energy storage and structural components of cells
Include triglycerides (fats and oils), phospholipids, and steroids
Examples: cholesterol, phosphatidylcholine, triolein

Proteins

Perform a wide range of functions: structural, enzymatic, transport, and storage
Primary structure: sequence of amino acids
Secondary structure: α-helices and β-pleated sheets

Protein Structure, Folding, and Function

Myoglobin

Oxygen storage protein in muscles
Has a hydrophobic pocket that binds oxygen

Hemoglobin

Oxygen transport protein in red blood cells
Tetrameric structure with each subunit containing a heme group

Lysozyme

Enzyme that breaks down bacterial cell walls
Hydrolyzes peptidoglycan, a component of bacterial cell walls

Ribonuclease A

Enzyme that breaks down RNA
Hydrolyzes the phosphodiester bond between nucleotides

Carboxypeptidase and Chymotrypsin

Digestive enzymes that break down proteins
Carboxypeptidase cleaves peptide bonds at the C-terminus, while chymotrypsin cleaves at specific internal sites

Enzyme Kinetics

Enzyme regulation involves controlling enzyme activity to achieve desired outcomes
Enzyme inhibition can be competitive, non-competitive, or uncompetitive, affecting substrate binding and enzyme activity

Vitamins and Coenzymes

Vitamins are essential nutrients that cannot be synthesized by the body
Coenzymes are molecules that assist enzymes in catalyzing reactions

Metabolism and Bioenergetics

ATP (adenosine triphosphate) is the primary energy currency of the cell
Generation of ATP involves cellular respiration and photosynthesis
Utilization of ATP involves energy-requiring processes like muscle contraction and transport

Metabolic Pathways

Glycolysis: converts glucose into pyruvate, generating ATP and NADH
TCA (tricarboxylic acid) cycle: converts pyruvate into acetyl-CoA, generating ATP, NADH, and FADH2
Pentose phosphate pathway: generates NADPH and pentoses from glucose
Oxidative phosphorylation: generates ATP from electron transport chain
Gluconeogenesis: generates glucose from non-carbohydrate sources
Glycogen metabolism: stores and breaks down glycogen, a complex carbohydrate
Fatty acid metabolism: breaks down fatty acids to generate ATP and NADH

Nitrogen Metabolism

Nitrogen fixation: converts atmospheric nitrogen into ammonia
Amino acid metabolism: involves synthesis and breakdown of amino acids
Nucleotide metabolism: involves synthesis and breakdown of nucleotides

Photosynthesis

Calvin cycle: converts CO2 into glucose using ATP and NADPH from light-dependent reactions

Description

Assess your knowledge of biomolecules, including amino acids, carbohydrates, lipids, proteins, and nucleic acids, as well as protein structure and function. Learn about the importance of water and the structure and function of various proteins.