Psio Exam Block 1

Anatomy

The study of structure.

Physiology

The study of function.

Structure-Function Relationship

The link between the structure of an anatomical feature and its function.

Metabolism

The sum of all chemical processes in the body.

Catabolism

The breakdown of larger molecules into smaller ones, creating energy.

Anabolism

The construction of larger molecules from smaller ones; synthesizes necessary materials for life.

Responsiveness

The ability to detect and respond to changes in the internal or external environment.

Growth

Increase in number or size of cells or the material between cells.

Differentiation

Specialization of cells for a specific function.

Reproduction

Formation of new cells or new individuals.

Levels of Biological Organization

Structural hierarchy from chemical, cellular, tissue, organ, system to organism level.

Homeostasis

The condition in which the body's internal environment remains relatively constant within physiological limits.

Negative Feedback Loop

A system where the original stimulus is reversed; most feedback systems in the body.

Positive Feedback Loop

A system that enhances the original stimulus, such as during childbirth.

Scientific Method

A systematic approach to investigate phenomena, incorporating observation, hypothesis/prediction, testing, analysis and conclusion, and development of a new hypothesis.

Hypothesis

A specific and testable question formed based on observation.

Physiological Limits

The boundaries within which the body operates effectively; includes factors like heat, moisture, and pressure.

Equilibrium

A state of balance between opposing forces.

Steady-State

A condition where all processes are balanced but not necessarily at equilibrium.

Feedback Loop

A process where the body responds to changes in the internal environment.

Chemical Reaction

Involves the making and breaking of chemical bonds, bc breaking bonds is difficult there needs to be a manipulation of the energy stored in these bonds.

Catalysts

Compounds that speed up reactions by reducing the amount of energy required to get them started.

Enzymes do what?

Biological catalysts that lower the activation energy for reactions.

How do enzymes lower activation energy?

Enzymes create an ideal environment for reactions, reduce randomness of collisions between molecules, and bring substrates together in the correct orientation.

Lactose

A sugar that can be broken down into glucose and galactose by the enzyme lactase; individuals with lactose intolerance have missing or defective lactase enzymes.

Aqueous Environment

Approximately 60% of body weight is water, contained in intracellular (ICF, inside) and extracellular fluid (ECF, outside) compartments.

Body Fluid Compartments

ICF is all fluids within cells, and ECF is all fluids outside cells, including interstitial fluid (ISF) and plasma.

Buffering Systems

Help maintain pH of body fluids within narrow ranges.

Organic Compounds

Always contain carbon and hydrogen.

Types of Lipids

Include monomers like glycerol and fatty acids and polymers like triglycerides; functions include energy storage, structural storage, and hormone synthesis.

Types of Carbohydrates

Monomers like monosaccharides (e.g., glucose) and polymers like polysaccharides (e.g., glycogen); primary energy source and energy storage.

Types of Proteins

Monomers are amino acids, forming polymers known as polypeptides; functions include cell machinery and muscle contraction.

Types of Nucleic Acids

Monomers are nucleotides; polymers include DNA and RNA, involved in heredity and protein structure.

High Energy Phosphate (ATP)

Adenosine triphosphate, transfers energy to power cellular activities.

Chemical Bonds

Types include ionic bonds (electrons transferred) and covalent bonds (electrons shared).

Polar vs. Non-polar Molecules

Polar molecules are hydrophilic (water-loving), while non-polar molecules are hydrophobic (water-fearing). Non-polar = equal sharing, polar = unequal sharing.

Amphipathic Molecules

Have both hydrophilic and hydrophobic regions, important for detergents and emulsifiers in biological systems.

Water as a Solvent

Excellent at dissolving polar substances due to its polar nature; cannot dissolve non-polar substances, like oil.

ECF = ISF + Plasma, what does this mean?

This equation signifies that the extracellular fluid (ECF) is composed of interstitial fluid (ISF) and plasma, highlighting the relationship between these two components of body fluid compartments.

Reactions in the human body depend primarily on temperature, orientation of molecules or chemical concentrations?

The concentration of molecules. In physiology, we typically reference concentrations within bodily fluids, examples being, blood calcium, blood glucose.

Cation ,what is it?

An atom that donates (loses) electrons and becomes a positive (cat = good)

Anion, what is it?

An atom accepts the electrons and becomes negative (Onion = bad)

Which type of bond is weak, but when there are many bonded together, provides stability?

Hydrogen bonds.

Cell Theory

Cells are the building blocks of animals and plants; they arise from pre-existing cells; they are the smallest unit having all the functions of living systems; the homeostasis of high levels of biological organization arises from coordinated activity of cells.

Plasma Membrane

The cell membrane; it acts as a barrier and interaction surface, also known as plasmalemma, that lets certain things in and out.

Nucleus

Contains the genetic material of a cell (DNA).

Cytoplasm

Everything between the membrane and the nucleus, consisting of intracellular fluid (cytosol) and organelles.

Cytosol

The intracellular fluid within the cytoplasm, excluding organelles.

Organelles

Subcellular structures with specific functions contained within the cytoplasm.

Smooth ER

A type of endoplasmic reticulum involved in lipid synthesis and detoxification.

Rough ER

A type of endoplasmic reticulum studded with ribosomes that synthesizes proteins.

Golgi Apparatus

An organelle that modifies, sorts, and packages proteins and lipids for secretion or delivery to other organelles.

Ribosomes

Molecular machines that synthesize proteins by translating mRNA.

Physiological Membrane Composition

Main components of membranes are lipids, proteins, and carbohydrates.

Phospholipid Structure

Amphipathic molecules with a polar head region (hydrophilic) and a non-polar tail region (hydrophobic) capable of spontaneous self-assembly.

Phospholipid Bilayer

Structure where nonpolar tails are oriented toward the inside and polar heads face the outside.

Liposomes

Cell-shaped structures formed by a phospholipid bilayer, containing polar substances inside.

Fluid Mosaic Model

Describes how membrane proteins are free to move laterally throughout the cell membrane.

Membrane Fluidity

The phospholipids and proteins in the membrane can move laterally, providing organization and support, and allowing for self-sealing if punctured.

Integral Proteins

Amphipathic proteins that extend into or completely across cell membranes, facilitating molecular transfer.

Peripheral Proteins

Polar proteins attached to the inner or outer surface of the membrane that can be easily removed.

Protein Structure Levels

Primary (amino acid sequence), Secondary (repeating patterns), Tertiary (3D folding), Quaternary (multiple peptides forming a complex).

Amino Acid

Composed of an amino group, a carboxyl group, and a variable R group.

Membrane Function Variation

Differences in membrane function arise primarily from the variety of proteins present in the membrane.

Membrane Functions

Barrier, Organization, Transport, Reaction/Response.

Selectively Permeable Membrane

The plasma membrane allows for concentration and electrical gradients between the cytosol and extracellular fluid (ECF).

Passive Transport

Movement of substances down their concentration gradient (high to low) without the need for energy.

Active Transport

Movement of substances against their concentration gradient (low to high) that requires energy from the cell (ATP).

Diffusion

The movement from high to low concentration; net diffusion is proportional to the concentration gradient.

Hydrophobic Substances in Passive Transport

Hydrophobic substances like gasses (O2, CO2), fatty acids, steroid hormones, and fat-soluble vitamins can passively cross the membrane.

Osmosis

The passive flow of water across a semipermeable membrane, moving from low solute concentration to high solute concentration.

Aquaporins

Integral membrane proteins that facilitate the transport of water across the plasma membrane.

Concentration Gradient

A difference in concentration of a substance across a space; drives the process of diffusion.

Role of Hydrostatic Pressure

Hydrostatic pressure can counteract osmotic pressure, balancing the flow of water across a membrane.

Facilitated Diffusion

A type of passive transport that involves carrier or channel proteins to help hydrophilic substances cross the membrane.

What does it mean for active transport to be symporter?

A type of secondary transporter that moves two substances in the same direction against the gradient.

What does it mean for active transport to be antiporter?

A type of secondary transporter that moves two substances in opposite directions across the membrane.

Characteristics of Carrier Transport

Carriers are saturable, have a finite number of transporters, and are selective for specific substrates.

Primary Active Transport

Direct use of ATP to transport molecules, e.g., the sodium-potassium pump (Na+/K+ ATPase).

IN primary active transport in the Sodium-Potassium Pump (Na+/K+ ATPase) what is the result after hydrolyzing 1 ATP?

For every 1 ATP hydrolyzed, it pumps 3 Na+ ions out of the cell and 2 K+ ions into the cell.

Vesicular Transport

Bulk transport of particles using vesicles. (The little transport molecules that look like there walking as they cross parts of the cell.)

Endocytosis

The process of transporting substances into a cell.(uptake)

Exocytosis

The process of transporting substances out of a cell. (release)

Transcytosis

The process of taking substances into a cell, moving them across the cell, and releasing them. (uptake —> move across cell —> rrelease)

Resting Membrane Potential

The electrical potential difference across the plasma membrane of a cell at rest, typically around -70 mV.

Sodium-Potassium ATPase Pump (Na+/K+ ATPase)

A transport protein that maintains the ion concentration gradients for sodium (Na+) and potassium (K+) by pumping 3 Na+ ions out of the cell and 2 K+ ions into the cell for each ATP used.

Permeability to K+

At rest, the membrane is primarily permeable to potassium ions (K+) through potassium leak channels.

Ion Concentration Gradients

The differences in Na+ and K+ concentrations across the plasma membrane that contribute to the resting membrane potential.

Electrical Gradient

The force acting on ions based on the charge difference across the membrane, influencing the movement of K+ ions.

Charge Separation

The buildup of potential energy across the membrane due to differing concentrations of ions, contributing to the resting membrane potential.

Electrical Potential Difference (PD)

The potential energy stored across the membrane of a living cell at rest, measured in millivolts (mV), typically from -50 mV to -100 mV.

Channel-Mediated Ion Permeability

Regulation of ion channel activity that allows cells to generate electrical signals by altering membrane potential.

Ligand-Gated Ion Channels

Ion channels that open in response to the binding of a signal molecule (ligand) to the channel protein.

Voltage-Gated Ion Channels

Ion channels that open when the membrane potential becomes less negative, facilitating depolarization.

Mechanically-Gated Ion Channels

Ion channels that open in response to mechanical distortion of the membrane, such as stretching.