Biochemistry of Muscles

The linear arrangement of amino acids in a protein, like beads on a string.

The 3D arrangement of the polypeptide backbone, mainly due to hydrogen bonding, forming structures like alpha helix and beta sheets.

The overall 3D shape of a protein, influenced by interactions between side chains of amino acids.

The arrangement of multiple polypeptide chains (subunits) to form a functional protein.

The pH at which a protein has no net charge.

The process of solidifying proteins, often due to heat, changes in pH, or heavy metals.

The coiled shape of a protein held by hydrogen bonds between amino acids.

A sheet-like structure in proteins formed by hydrogen bonds between polypeptide chains.

The hydrogen bonds between the carbonyl group and amino group of amino acids in a protein, playing a crucial role in protein structure.

The process of breaking down the structure of proteins, disrupting their biological activity.

The most basic level of protein structure, formed by the sequence of amino acids.

The folding of a polypeptide chain into a helix or sheet shape, stabilized by hydrogen bonds.

The three-dimensional shape of a protein molecule, formed by interactions between amino acid side chains.

The arrangement of multiple polypeptide chains to form a functional protein.

Proteins that contain only amino acids.

Proteins that contain amino acids and additional non-protein components.

Proteins that provide all the essential amino acids in the right proportions for growth and repair.

Proteins that lack one or more essential amino acids.

The process of breaking down peptide bonds in proteins, producing smaller peptides and amino acids.

The protein responsible for storing oxygen in muscles, giving them their color. Its concentration varies depending on the muscle's activity level.

A protein found in muscle cells that binds to calcium ions (Ca2+) and triggers muscle contraction.

Thick filaments in muscle cells, made up of 200-400 myosin molecules. Responsible for muscle contraction.

Thin filaments in muscle cells, made up of actin, tropomyosin, and troponin. Interact with thick filaments during muscle contraction.

A protein that forms thick filaments in muscle cells and is essential for muscle contraction. It binds to actin and uses energy from ATP to move.

The globular protein monomer that makes up thin filaments in muscle cells. It interacts with myosin during muscle contraction.

The double helix structure of actin, which is found in thin filaments. It forms long chains.

A protein that binds to actin in thin filaments. It helps regulate muscle contraction.

A protein complex that binds to tropomyosin. It plays a crucial role in muscle contraction by allowing or blocking myosin binding to actin.

The energy source used by myosin for movement during muscle contraction. It is hydrolyzed to release energy.

Muscle contraction is the process where muscle tissue shortens and generates tension.

Muscle contraction is triggered by an electrical signal that travels through motor nerves and reaches the muscle fibers at the neuromuscular junction.

The myosin head binds to actin, forming a cross-bridge. This pulls actin towards the center of the sarcomere, causing muscle shortening.

ATP provides energy for muscle contraction, powering the detachment of myosin from actin and resetting the myosin head for the next cycle.

Calcium ions bind to troponin, which moves tropomyosin away from the myosin binding sites on actin, allowing the myosin head to attach.

When the muscle is relaxed, myosin is bound to ATP, but the hydrolysis products (ADP and phosphate) are not released. This 'cocks' the myosin head, ready for contraction.

A protein complex in muscle that regulates muscle contraction. It consists of three subunits: troponin C (binds calcium ions), troponin I (inhibits actin binding), and troponin T (binds to tropomyosin).

A protein complex formed when myosin heads bind to actin filaments. This interaction is crucial for muscle contraction, as it generates the force needed for the sliding filament mechanism.

The main form of glucose storage in muscles. This polysaccharide provides a readily available energy source for muscle contraction.

A molecule that can transfer a phosphate group to ADP, regenerating ATP for muscle contraction. This process is important for short bursts of muscle activity.

Dipeptides that are found in muscles and may help reduce muscle fatigue, enhancing muscle contraction.

A molecule that acts as a carrier, transporting fatty acid residues across the mitochondrial membrane for energy production. This is important for muscle energy metabolism, especially during prolonged activity.

Branched-chain amino acids (BCAAs) are essential for muscle protein synthesis and energy production. They are a major source of amino groups for gluconeogenesis.

The primary function of muscles is to convert chemical energy (ATP) into mechanical work, allowing for movement.

Muscles play a vital role in respiration, digestion, blood circulation, and excretion.

Muscles contain low-molecular-weight organic compounds containing nitrogen. These include nucleotides like ATP, ADP, and AMP, as well as creatine and phosphocreatine.