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psio201

1. Discuss the inuence of concentra2on gradients and distance on the rate of diusion.

Review of the last lecture

2. Dene osmosis. Predict the direc2on of net osmo2c water ow. Compare and contrast the concepts of osmolarity and tonicity. (T&D p 72-73).

3. Compare and contrast the characteris2cs that dis2nguish passive diusion from carrier-mediated transport; include a discussion of two diagnos2c characteris2cs of carrier-mediated transport.

4. Compare and contrast the characteris2cs of facilitated diusion and ac2ve transport.

Review of the last lecture

5. Compare and contrast the characteris2cs of primary and secondary ac2ve transport.

6. List the categories of vesicular transport and describe a representa2ve example of each.

Carrier-Mediated Transport B. Categories of Carriers

1. Facilitated Diusion

2. Ac4ve Transport

A. Primary AcFve Transport

Immediate energy source: ATP

B. Secondary AcFve Transport

Immediate energy source: trans-membrane ion gradients

Sources of energy

adenosine triphosphate

outsideinside

membrane

X

X

Primary ActiveTransport X includes several

inorganic caFons:

Na+ K+ H+ Ca2+

X can also include a variety of organic electrolytes

ADP+Pi

ATP

Na+/K+ Pump & ATP As Its Energy Source

3 Na+ ions removed from cell as 2 K+ brought into cell, with 1 ATP hydrolyzed

Na+,K+-ATPase represents ~10% of your basal metabolic rate!

outsideinside

membrane

AA

Secondary ActiveTransport

XX

X is typically Na+

Secondary AT is the most common strategy used to accumulate nutrients (organic and inorganic)

AnFporters and Symporters

Vesicular Transport of ParFcles

Endocytosis = bringing something into cell

Exocytosis = release something from cell

Refer to T&D, pp 75-78

OrganizaFon of the Cytoplasm

cytosol vs. organelles

Two Categories of Organelle

1. Membranous e.g. Plasma membrane Nucleus Mitochondria

2. Non-Membranous e.g. Cytoskeleton Ribosomes

Cytoskeleton

A. Microlaments - strands of protein (ac2n)

1. Connect organelles to membranes

2. Inuence cell mo2lity and shape

B. Intermediate laments - kera2ns

1. Structural stability

C. Microtubules - strands of tubulin

1. Inuence cell structure and shape

2. Mo2lity - organelle movement - cilia/agella

Non-Membranous Organelles B. Cilia and Flagella

Cell mo2lity

A. Centrioles/ Centrosomes

Cell mo2lity/Cell division

Non-Membranous Organelles

C. Microvilli

Increase surface area of plasma membrane

D. Ribosomes

Site of protein synthesis

B. Mitochondria - major site of cell energy metabolism

Membranous Organelles

A. Nucleus (later lecture)

OxidaFve ATP producFon

ATP - Adenosine Triphosphate

ATP ADP + Pi

work

energymetabolismMitochondria Cytoplasm (glycolysis)

ATPATP

glycolysisGlucose

Glucose

pyruvate

mitochondrian

plasma membrane

Pyr

TCA

O2

CO2

ATP

outermito-membrane

innermito-membrane

respiratoryenzymes

OxidaFve PhosphorylaFon

1. Consumes O2 2. Produces CO2 3. Ecient produc4on of ATP

Enzyma2cally-controlled breaking of bonds

Endoplasmic ReFculum

Membranous network

4 funcFons

1. Lipid & protein synthesis

2. Storage (protein; Ca2+)

3. Transport within cell

4. Detoxica2on

Endoplasmic ReFculum

Membranous network

lipid synth; Ca2+ storage protein synth & storage

2 structural/funcFonal categories

1. Smooth ER 2. Rough ER

Golgi Apparatus

Site of packaging and processing of protein products for secreFon

Integrated Secretory AcFvity of ER and Golgi

Lysosomes & Peroxisomes

Contains digesFve enzymes for turning over old cellular material; detoxicaFon

Terms and Concepts cytoskeleton microlaments acFn microtubules ribosomes mitochondria aerobic metabolism glycolysis ATP

endoplasmic reFculum (ER) smooth ER rough ER Golgi apparatus lysosome

Internet sites containing addi2onal (typically, more advanced) informa2on relevant to: 1. General tour of cell structure: h`p://www.johnkyrk.com/CellIndex.html

2. An extraordinary tour of selected cell structures and funcFons (this is the long version of the Inner Life of a Cell video I referenced previously) Inner Life of the Cell: h`p://mulFmedia.mcb.harvard.edu/media.html