KNES 259 Physiology - Highlight Reel

What is Cell Physiology?

The study of body functions and how body systems work together

The Cell - Nucleus

Responsible for: cell replication and repair. (normally 1 per cell;) EXCEPTIONS: RBC: no nucleus . MUSCLE: mulitnulceated

The Cell - Ribosomes

Makes proteins. Free (makes portions for the cell) --> ex)muscle, or attached

The Cell - Endoplasmic Reticulum (ER)

SMOOTH ER: calcium storage (skeletal, muscle), de-toxification (liver), steroid production (ovaries, testes). ROUGH ER: ribosomes attached, makes organelles, protein production for export, ex) pancreas

The Cell - Golgi Complex

Re-packages RER portions into a vesicle that can leave the cell (different membrane from the cell so it can leave) ex) pancreas

The Cell - Peroxisomes

OXIDATIVE ENZYMES: Metabolism - beta oxidation, lipid synthesis. Detoxify various waste products - makes hydrogen peroxide (coverts water with a catalase). ex) liver hepatocytes

The Cell - Lysosomes

Sac of digestive enzymes. Used for repair and removal of foreign matter (immune response). ex) WBC's - killer cells

The Cell - Proteosomes

LARGE PROTIEN COMPLEXES. Protein digesting organelles - digest tagged proteins (damaged or no longer needed). Quality assurance. With age, may be unable to normally remove proteins - causes build up of bad proteins.

The Cell - Cytoskeleton

COMPLEX PROTEIN NETWORK. Acts as "bone and muscle" of the cell. 3 elements - Microtubules, Microfilaments, Intermediate Filaments.

Cytoskeleton - Microtubules

Transport secretory vesicles. Form mitotic spindle during cell division - form + break down quickly. (thin) ex) tubulin.

Cytoskeleton - Microfilaments

Contractile systems. Muscle. Mechanical stiffeners. (fatter) ex) actin and myosin.

Cytoskeleton - Intermediate Filaments

Help resist mechanical stress. Hair, skin - collagen. (most complex) ex)keratin

The Cell - Cilia

Directional movement of particles. Beat upwards in lungs. ex) trachea, uterine tubes

The Cell - Flagella

On moving cell. ex) sperm

The Cell - Mitochondria

ENERGY ORGANELLE. Site of ATP production. Enzymes for TCA (tricarboxylic acid) and ETC (electronic transport chain). Powerhouse.

Plasma Membrane Structure

Physical barrier --> gateway for exchange --> communication --> cell structure

Cell Membrane Structure

Phospholipids and Cholesterol

Phospholipids

Choline head - polar: water soluble. Fatty acid tails - non-polar, creates barrier for flow.

Glycocalyx

Glycoprotiens and glycolipids on surface of cell - cell identity, and cell orientation. Helps cell align, cell identification, creates room for cell to move.

What are the Two Type of Membrane Proteins?

Integral (transmembrane) Proteins

Peripheral Proteins

Membrane Proteins - Ion Channels

Forms a pore though which a specific ion can flow to get across membrane. We can't open or close it. INTEGRAL

Membrane Proteins - Carriers

Transports a specific substance across membrane by undergoing a change in shape. INTEGRAL

Membrane Proteins - Receptor Sites

Recognizes specific ligand and alters cell's function in some way. Tells cells to do same things. INTEGRAL

Membrane Proteins - Enzymes

Catalyzes a reaction inside or outside cell (depending on which direction the active site faces). INTEGRAL AND PERIPHERAL

Membrane Proteins - Pores

Open up channels through them. Specific to H2O. INTEGRAL

Membrane Proteins - Structural

Shapes the structure and skeleton of cell. INTEGRAL

Membrane Proteins - Cell Adhesion (Cell Junctions)

Anchors filaments inside and outside the plasma membrane, providing structural stability and shape for the cell. INTEGRAL AND PERIPHERAL

Membrane Proteins - Cell Identity Marker

Distinguishes your cells from anyone else's (except for identical twins). GLYCOPROTEIN

What are Membrane Gradients?

Power movement without ATP

Membrane Gradients - Concentration Gradient

Difference in substance concentration across a membrane

Membrane Gradients - Electrical Gradient

Difference in charge (conc. of ions)

Membrane Gradients - Electrochemical Gradient

Combination of both

What is Diffusion?

Two - way movement. Consider net movement.

Membrane Transport - Simple Diffusion

Net diffusion from high to low concentration (due to particles random collisions). Small molecules (oxygen, carbon dioxide), steroids.

What does the rate of diffusion depend on?

- Temperature

- Concentration gradients

- Diffusion distance

- Mass of diffusion substance

Diffusion Across a Membrane (and what it depends on)

Particle must be permeable

- Permeability

- Surface area

- Gradient

- Temperature

Membrane Transport - Osmosis

Net diffusion of water down its own concentration gradient. "Pulled" by non-diffusible particles.

Whats the Difference Between Osmosis and Diffusion?

Diffusion refers to the movement of molecules from an area of high concentration to an area of lower concentration. Osmosis is a type of diffusion specifically for water molecules moving across a semi-permeable membrane

What is Tonicity?

It determines osmosis. Tonicity: # go non-diffusible particles. "Water magnets"

What are the types of Tonicity?

ISOTONIC: solutions are the same / no net osmosis

HYPOTONIC: fewer non-diffusible particles - cells swell

HYPERTONIC: more non-diffusible particles - cells shrink

Water moves from hypotonic to hypertonic.

Facilitated Membrane Transport Diffusion

Role of plasma proteins - pores, channels (protein is channel only) , carriers. Movement can only occur if channels is open. Substance moves in though con. gradient. CHANNEL MEDIATED OR CARRIER MEDIATED.

Active Transport

Against gradient - requires energy (ATP). MUST USE CARRIER. Na K Pump.

Co-Transport

Secondary active transport. Powered by ( ) gradient of one solute. Moves 2nd solute against gradient. AKA symporter

Counter Transport

Similar to co-transport, but each molecule moves in opposite directions. AKA anti-porter

Vesicle Transport

Endocytosis (enter) Exocytosis (exit)

Receptor-Mediated Endocytosis

Binds molecules and then takes in as vesicle. BINDS then takes out.

Phagocytosis

Breaking down. Immune response in WBCs. Still engulfing - focuses more on breaking down.

Pinocytosis

Most cells can move water into the cell in bulk flow. In our out. Uses a vesicle.

Epithelial Transport

Combines both diffusion and active transport for movement. (not on midterm)

Mitosis Phases

Interphase (before mitosis), Prophase, Prometaphase, Metaphase, Anaphase, Telophase and Cytokinesis

Mitosis - Prophase

Chromatin in nucleus condenses into chromosomes. Nuclear wall degenerates. Centrosomes start to move apart. (get rid of nuclear membrane so it can divide)

Mitosis - Pro-metaphase

Nuclear envelope disappears. Spindles form chromatic to centrosomes. Kinetochore proteins appear (become visible)

Mitosis - Metaphase

(middle) Centromeres of chromosomes line up at the metaphase plate. Mitotic spindles start to form - ready to pull apart.

Mitosis: Anaphase

Centromeres of chromosomes split. Kinetichore microtubules sister chromatids move toward opposite poles of the cell (pulled apart). Ones pulling get shorter. Non-Kinetochore microtubule - overlap and push against each other, elongating the cell.

Mitosis - Telophase

Mitotic spindles dissolve. Chromosomes becomes chromatin. New nuclear membrane forms (undoing prophase)

Mitosis - Cytokinesis

Division of cytoplasm. Occurs with telophase. Cleavage furrow pinches cell in two (actual division into 2 daughter cells). After this, new cells enter interphase.

What is Meiosis?

Sexual reproduction. Produces a haploid set of chromosomes (eggs and sperm). Chromosomes replicate once. 2 cell divisions - Meiosis 1, Meiosis 2.

Meiosis 1 vs 2

1 - reduces chromosomes from diploid to haploid. 2 - produces 4 haploid daughter cells.

Meiosis - Crossing Over

Prophase 1 (split over the metaphase line before this). Increases genetic variability. Produces chromosomes that carry genes from 2 different parents.

Meiosis vs Mitosis

Meiosis - 23 pairs (all look the same). Mitosis - 46 singles (all unique - new).

What causes Down syndrome?

trisomy 21, extra copy of chromosome 21

Genetics - Phenotype

Its physical appearance of a specific character

Genetics - Genotype

The genetic makeup (alleles) that determine the physical appearance

Genetics - Character

A heritable feature, such as eye colour or hair colour

Genetics - Trait

A variant of a character, such a blue eyes or brown eyes

Genetics - P Generation

The true breeding parents

Genetics - F1 Generation

Hybrid offspring of the P generation

Genetics - F2 Generation

When F1 individuals self - pollinate

Genetics - Alleles

Inherited characteristics on the genes (get on from each parent)

Genetics - Dominant Allele

Determines the organisms appearance

Genetics - Recessive Allele

Has no noticeable effect on the organisms appearance

Genetics - Homozygous

Has a pair of identical alleles for that gene. Either dominant or recessive.

Genetics - Heterozygous

Has a pair of alleles that are different for that gene

Genetics - Pleiotropy

One gene, many effects

Genetics - Polygeny

Many genes affecting one trait

Genetics - Co-dominance

More than one dominant gene can be displayed

Genetics - Incomplete Dominance

Intermediate trait is seen with heterozygous genotypes

What is DNA Replication?

Each strand acts as a template for building a new strand. Parent unwinds - two daughter built. Semi-conservative: each daughter has 1 parent cell. Begins at sites of origins.

DNA Replication - Helicase

UNWINDS THE HELIX. Binding proteins stabilize template strands. Topoisomerase stabilizes the "over-twist" ahead of helices.

DNA Replication - Primase

"Primes" strands with RNA

DNA Replication - Polymerase 3

Elongates strand - adds nucleotides to 3' end only. Reads parent strand from 3' to 5'. Builds daughter from 5' to 3'.

DNA Replication - Polymerase 1

Replaces primer RNA

DNA Replication - Ligase

"Glues" back together

DNA Replication - Leading Strand

Synthesize a complimentary strand continuously - moving towards replication fork. Primase adds RNA primer once --> DNA Poly 3 builds continuously towards fork --> Poly 1 replaces primes --> Ligase binds it to other segment (initial section)

DNA Replication - Lagging Strand

Synthesize as a series of Okazaki fragments (segments) - joined together by ligase. Moves away from fork. Primase adds short primer sequence --> DNA Poly 3 adds nucleotides to 3' end until it reaches next primer - Okazaki fragment --> DNA Poly 1 replaces primer nucleotides with DNA --> Ligase bonds segments together.

Fuel - Glucose

1 glucose yields 38 ATP. Oxygen required for full aerobic process - anaerobic (glycolysis - only yields 2 ATP). Uses about 40% of energy (turned into ATP) stored in glucose - rest is lost as heat. FIRST CHOICE FOR FUELS - QUICK TO BREAK DOWN.

Fuel - Proteins

Amino acids converted to ketoacids (malate, future, citrate). Lowest overall ATP yield. LAST RESORT FOR ENERGY (ex) starvation, high protein intake)

Fuel- Fat

Uses beta oxidation (slow as start - not used initially) to form Acetyl CoA - then enters TSA cycle. High energy yield (ATP). Most efficient storage of energy.

Cellular Respiration

Breakdown of glucose or other fuels in the presence of oxygen to yield ATP

FOUR STAGES:

1) Glycolysis: breakdown of sugar

2) Preparatory Step: gets it into mitochondria

3) Citric Acid Cycle: blow apart rest of molecule

4) Electron Transport Chain: ETC ETS

Cell Resp. - Glycolysis

2 ATP in - 1 glucose in. 4 ATP out (but we only GAIN 2). 2 NADH out. 2 pyruvate. Net is 2-2-2. Anaerobic.

Cell Resp. - Citic Acid Cycle

Loss of CO2. Irreversible. Pyruvate becomes Acetyl CoA.

Cell Resp. - Preparatory Step

1 Acetyl CoA in - 3 NADH out, 1 ATP out, 1 FADH out: 2 cycles. 6-2-2.

Cell Resp. - ETC

8 NADH in, 2 FADH in. Forms ATP - 32-34 ATP.

Process of Proteins

transporters/carriers

channel/pores

antibodies

storage/structure

hormones/receptors

contractile proteins

enzymes

Types of Cell Junctions

Gap Junctions

Tight Junctions

Desmosomes - Adhering Junctions

Cell Junctions - Gap Junctions

Allows movement of ions - transmission of charge (electrical impulse) --> small holes (pores)

ex) heart, gut

Cell Junctions - Tight Junctions

Allows NO movement between cells - we don't wanna absorb just anything

ex) intestine, blood-brain barrier

Cell Junctions - Desmosomes

Structural Junction. Withstands stress (growing) - really hard to pull apart.

ex) skin, uterus

What are Tissues?

Cells with similar structure and function

4 TYPES:

1) Epithelial

2) Connective Tissue

3) Nerve

4) Muscle

Epithelial Tissue

Covering sheets - covers every single surface everywhere. ex) epithelial lining, skin

GLANDS - exocrine, endocrine. TYPES: SIMPLE, AND STRATIFIED. - Cuboidal, columnar cells, and Squamous cells