Biophysics

These flashcards cover fundamental concepts in biophysics, cellular processes, and muscle physiology, aiding in your exam preparation.

What is biophysics?

The branch of science that applies physics and chemistry principles, mathematical analysis, and computer modeling to biological systems.

What are subatomic particles?

Electrons, protons, and neutrons.

What are examples of macromolecules in biophysics?

Proteins, DNA molecules.

What is the smallest living unit of the body?

The cell.

What are the four basic tissue types?

Nervous, muscle, epithelial, and connective tissue.

What are examples of organ systems?

Skeletal, digestive, cardiovascular, respiratory, and urinary systems.

What percentage of total body weight is body fluid?

60%.

What is the difference between intracellular fluid (ICF) and extracellular fluid (ECF)?

ICF is rich in potassium and proteins; ECF is rich in sodium and contains few proteins.

What is homeostasis?

The process of maintaining a stable internal environment despite external changes.

What are the three components of homeostatic control mechanisms?

Receptor, control center, and effector.

What is negative feedback?

A system that produces a change opposite to the initial stimulus.

Give an example of negative feedback.

Body temperature regulation.

What is hypothermia?

A condition where body temperature drops below the normal range, potentially leading to coma and death.

What is positive feedback?

A mechanism that intensifies a change in the body’s physiological condition.

Give an example of positive feedback.

Onset of contractions before childbirth.

What are biomolecules?

Molecules synthesized by living organisms containing carbon.

What are the four major biomolecule groups?

Carbohydrates, lipids, proteins, and nucleotides.

What makes carbohydrates polar?

Hydroxyl (-OH) groups.

What is the process that links monosaccharides together?

Condensation.

What are the three types of carbohydrates?

Monosaccharides, disaccharides, and polysaccharides.

Why is glycogen stored instead of monosaccharides?

To prevent osmotic pressure that could cause cells to swell and burst.

What are the five main classes of lipids?

Triglycerides, ketones, phospholipids, eicosanoids, and steroids.

What are the structural components of a triglyceride?

Glycerol backbone + 3 fatty acids.

What makes phospholipids unique?

They are amphipathic, containing both hydrophilic and hydrophobic regions.

What is the most common steroid?

Cholesterol.

What are the four levels of protein structure?

Primary, secondary, tertiary, and quaternary.

What is a peptide bond?

The bond linking amino acids in a protein.

What are fibrous proteins?

Structural proteins like collagen and myosin.

What are globular proteins?

Functional proteins like enzymes and receptors.

What is the function of glycoproteins?

Involved in cell recognition and immune response.

What are the components of a nucleotide?

A five-carbon sugar, a nitrogenous base, and phosphate groups.

What are the two types of nitrogenous bases?

Purines (adenine, guanine) and pyrimidines (cytosine, thymine, uracil).

What are the two types of nucleic acids?

DNA and RNA.

What are the two main components of a cell?

Nucleus and cytoplasm.

What is the plasma membrane composed of?

Phospholipids, cholesterol, proteins, and carbohydrates.

What is the function of the Golgi apparatus?

Processes and packages proteins for transport.

What is the main function of mitochondria?

ATP production.

What is the cytoskeleton?

A network of protein fibers providing cell structure and support.

What are the three types of cytoskeletal filaments?

Microfilaments, intermediate filaments, and microtubules.

What is the function of ribosomes?

Protein synthesis.

What is transcription?

The process where DNA is copied into mRNA.

What is translation?

The process where mRNA is used to assemble proteins.

What enzyme catalyzes transcription?

RNA polymerase.

What is the function of tRNA?

Carries amino acids to the ribosome during translation.

What is the role of the leader sequence in proteins?

Determines the destination of newly synthesized proteins.

What is the importance of the endoplasmic reticulum?

Rough ER aids in protein synthesis, smooth ER in lipid metabolism.

What does the Na+/K+ pump do?

Actively transports Na+ out and K+ into the cell.

What is a lysosome?

An organelle that digests cellular waste.

What is apoptosis?

Programmed cell death.

What is an example of an amphipathic molecule?

Phospholipids.

What are the primary biomolecules used for energy?

Carbohydrates, lipids, proteins, and nucleic acids.

Where does most biological energy originate?

Solar energy.

What is metabolism?

The sum of all chemical reactions in the body.

What are the two types of metabolic reactions?

Catabolism (breakdown) and anabolism (synthesis).

What is a calorie?

The amount of energy needed to raise 1 kg of water by 1°C.

What is the difference between a calorie and a Calorie?

1 Calorie (kcal) = 1,000 calories.

What are the three types of metabolic reactions?

Hydrolysis/condensation, phosphorylation/dephosphorylation, oxidation-reduction.

What is hydrolysis?

A reaction where water is added to break molecules apart.

What is condensation?

A reaction where water is removed to form larger molecules.

What is oxidation?

The removal of electrons from a molecule.

What is reduction?

The gain of electrons by a molecule.

What is kinetic energy?

Energy associated with motion.

What is potential energy?

Stored energy that can be converted into kinetic energy.

What does the first law of thermodynamics state?

Energy cannot be created or destroyed.

What does the second law of thermodynamics state?

Natural processes tend to increase entropy.

What is an exergonic reaction?

A reaction that releases energy.

What is an endergonic reaction?

A reaction that requires energy input.

What is an enzyme?

A protein that acts as a biological catalyst.

What is an apoenzyme?

The protein component of an enzyme.

What is a cofactor?

A non-protein substance required for enzyme function.

What is an example of an enzyme?

DNA polymerase.

What is the function of ATP synthase?

Synthesizing ATP from ADP and Pi.

What are the three steps of enzyme action?

Substrate binding, product formation, product release.

What is the lock-and-key model?

The enzyme’s active site has a specific shape that fits the substrate exactly.

What is the induced-fit model?

The enzyme changes shape slightly to fit the substrate.

What is the function of NAD+ and FAD?

Electron carriers in metabolic reactions.

What are coenzymes?

Organic molecules that assist enzyme function.

What is allosteric regulation?

The regulation of enzyme activity through molecules binding at a site other than the active site.

What is feedback inhibition?

A process where the product of a reaction inhibits the enzyme that produced it.

What is the role of ATP?

It acts as the primary energy currency in cells.

What are the two processes for ATP synthesis?

Substrate-level phosphorylation and oxidative phosphorylation.

What are the three stages of glucose oxidation?

Glycolysis, Krebs cycle, oxidative phosphorylation.

Where does glycolysis occur?

In the cytoplasm.

Where does the Krebs cycle occur?

In the mitochondrial matrix.

What is the main function of the electron transport chain?

Producing ATP via oxidative phosphorylation.

What is diffusion?

The movement of molecules from high to low concentration.

What is active transport?

The movement of molecules against their concentration gradient using energy.

What is the plasma membrane composed of?

Phospholipids, cholesterol, proteins, and carbohydrates.

What is simple diffusion?

Movement of molecules across the membrane without assistance.

What is facilitated diffusion?

Movement of molecules via transport proteins.

What is osmosis?

The passive transport of water across membranes.

What is the function of the Na+/K+ pump?

Moving Na+ out and K+ into the cell against their concentration gradients.

What is phagocytosis?

A form of endocytosis where the cell engulfs large particles.

What is pinocytosis?

A form of endocytosis where the cell engulfs fluid.

What is exocytosis?

The process of vesicles fusing with the plasma membrane to release contents.

What is the function of gap junctions?

Allowing direct communication between cells.

What is epithelial transport?

The movement of substances across epithelial cells.

What is the basement membrane?

A non-cellular layer that supports epithelial tissue.

What drives epithelial water transport?

Osmotic pressure gradients.

What is transcytosis?

The transport of macromolecules across a cell via vesicles.