Physiology Midterm HLSC 2P09

Molecular interactions

the ability of individual molecules to bind to or react with other molecules is essential for biological function

Phospholipids

similar to TAG but contain 2 FA + functional groups containing

steroids

rings of C-atoms linked together; e.g. cholesterol, cortisol, and sex hormones

nucleotides play important role in:

energy transfer, signal transduction

nucleic acids

-DNA and RNA

-2% body weight

-storage, expression, and transmission of genetic info

induced fit model of protein binding

molecular complementarity - the ligand and the binding site must be compatible, the shapes of the ligand and the binding site do not have to match exactly

Protein's affinity for a given ligand is measured by what?

The equilibrium constant and the dissociation constant

antagonists

Molecules that resemble the shape of the natural ligand, but block or inhibit the protein's physiological response upon binding

isoforms

slightly different versions of the same protein

factors affecting protein binding

activators, inhibitors, modulators

Inhibitors

competitive, irreversible, allosteric

modulators

pH + temp, covalent, concentration

cell basic functions

energy production, synthesis/storage, cellular communication, genetic info control

components of cell membrane

lipids, proteins, and carbohydrates

Nucleus

A part of the cell containing DNA, responsible for growth and reproduction

Golgi apparatus

A system of membranes that modifies and packages proteins for export by the cell

Peroxisomes

Contain enzymes that break down fatty acids and detoxify some foreign materials

Centrosomes

Coordinate the building and breaking of microtubules.

Epithelial

Protect the internal environment, regulate the exchange of material, or manufacture and secrete chemicals

Muscle

Generate and propagate electrical signals; has the ability to contract and produce force and movement

Connective

Extensive extracellular matrix that provides structural support and forms a physical barrier

Neural

Are excitable like muscle; include neurons and glial cells

Osmosis

The net movement of water across a membrane in response to a concentration gradient

Active Transport Processes

Vesicular transport, protein-mediated

Diffusion

movement of molecules from an area of higher concentration to an area of lower concentration

membrane receptors

integral membrane proteins that allow communication between the cell and the extracellular space

carrier proteins

Large, complex proteins with

multiple subunits. Bind with specific ligands and

carry them across the membrane

facilitated diffusion

no outside source of energy except a concentration gradient is needed to move molecules across the cell membrane

Endocytosis/pinocytosis

Pinching of membrane to form vesicles to bring things inside cells. Can be nonselective (bring in ECF) = pinocytosis or selective = receptor mediated

chemical work

the making and breaking of chemical bonds

transport work

movement of ions, molecules, and larger particles through membranes

mechanical work

movement of organelles, change of cell shape, muscle contraction

Hydrolysis-dehydration

Add or subtract a water molecule

addition-subtraction reaction

adds or removes function group from more than one substrate

ligation

Join two molecules together using enzymes known as synthetases and energy from ATP

Catabolism

Breakdown of large biomolecules to produce energy

Anabolism

Synthesis of large biomolecules using energy

Glycolysis

the breakdown of 1 glucose by enzymes, releasing energy and 2 pyruvic molecules.

citric acid cycle

Completes the breakdown of glucose by oxidizing a derivative of pyruvate to carbon dioxide.

constitutively active genes

genes that are continuously being read and converted to RNA messages (essential for ongoing cell functions)

regulated genes

genes whose activity is controlled in response to the needs of a cell or organism

Protein synthesis steps

1. gene activation

2. transcription

3. mRNA processing

4. translation

5. posttranslational modification

law of mass balance

if the amount of a substance in the body is to remain constant, any gain must be offset by an equal loss

Clearnace

the rate at which a material is removed from the blood by excretion, metabolism, or both through liver, kidneys, lungs, and skin

Two basic patterns of control mechanisms

1. Local control

2. Long-distance reflex control

reflex control

long-distance signaling and coordination through nervous and endocrine systems, can be broken down into response and feedback loops

response loop

stimulus, input signal, integrating center, output signal

feedback loop

Information about a homeostatic response that is sent back to the integrating centre

feedforward control

allows the body to predict that a change is about to occur and start the response loop in anticipation of the change

Physiology

The study of the normal functioning of a living organism and its component parts, including all its chemical and physical processes

mechanism

Mechanistic approach explains "how" they happen

Compartmentation

division of space into separate compartments

Biomolecules

carbohydrates, lipids, proteins, nucleotides

Biochemistry

Chemistry of living things

types of charbohydrates

monosaccharides, disaccharides, polysaccharides

Lingand

A molecule that binds to a protein at a binding site

Substrate

a specific type of ligand that interacts with an enzyme, facilitate catalytic reactions

law of mass action

When protein binding is at equilibrium, the ratio of the bound and unbound components remain the same

Agonist

Competing ligands that mimic each other's shape, activate the protein upon binding, and initiate a similar physiological response

Activators

proteolytic activation, cofactors, allosteric

Cytoplasm

Include all material inside the cell membrane except for the nucleus.

Lysosomes

Small spherical storage vesicles that contain powerful enzymes for the breakdown of foreign material. Digest and destroy invading microbes

Tonicity

the ability of a surrounding solution to cause a cell to gain or lose water

Cells in a hypotonic solution

water will rush into the cell, causing it to swell and possibly burst.

Cells in a hypertonic solution

Shrink as a result of water leaving the cell.

cells in isotonic solution

do not change size -no osmosis

Passive Transport Processes

simple diffusion, protein-mediated

active transport

requires an outside energy source (e.g., ATP) to move molecules against concentration gradient

Phagocytosis

Ingestion of very large particles such as bacteria, cells or portions of degenerating tissue into a phagosome

Exocytosis

Reverse of endocytosis. Fusion of vesicles with the membrane to secrete or expel the content (such as proteins and cellular waste)

Properties of living organisms

1. complex structure

2. Acquire, transform, store, and use energy

3. Sense and respond to environments

4. Maintain homeostasis

5. Store, use, and transmit information

6. Reproduce, develop, grow & die

7. emergent properties that cannot be predicted

8. Individuals adapt and evolve

oxidation-reduction reaction

Transfer electrons from one molecule to another.

ETS (electron transport system)

yields 32 ATP

Diseases fall into two general groups according to their origin:

internal causes, external causes

Pathophysiology

the study of body functions in a disease state

function

Teleological approach explains "why" events happen

Scientific Process

observation, experimentation, hypothesis, types of variables

scientific theory

hypothesis supported by data from multiple sources

organic molecules

carbon-based molecules

Charbohydrates

-Cn(H2O)n

-A hydrogen-oxygen atom ratio of 2:1

-provide cells with energy

Lipids

-carbon & hydrogen

-15% of body weight

-non polar molecules

classes of lipids

fats, monoacylglycerols (MAG), diacylglycerols (DAG), triglycerides (TAG)

nucleotides

building blocks of nucleic acids

Forms of DNA

A, B, Z

forms of RNA

mRNA, tRNA, rRNA

proteins

17% of body weight, significant in structure and function, made of amino acids

lumen

interior of any hollow organ

Endoplasmic Reticulum

A network of interconnected membrane tubes (rough and smooth)

Mitochondria

An elliptical organelle with a double wall, powerhouses, contain their own DNA

Ribosomes

Small dense granules of protein and rRNA - responsible for protein synthesis (fixed and free)

osmolarity

the number of particles per liter of solution (mOsM)

osmotic pressure

the minimum pressure that must be applied to a solution to halt osmosis

Aquaporins

water channel proteins

energy

the capacity to do work

Energy associated with reactions

activation, free, net free

Enzymes

Proteins that INCREASE the rate of chemical reactions

Metabolism

All of the chemical reactions that occur within an organism

Gene

a region of DNA that contains the information needed to make a functional piece of RNA

negative feedback

the response opposes or removes the original stimulus, which in turn stops the response loop

positive feedback

Feedback that tends to magnify a process or increase its output.