Cell Structures
Diffusion and Osmosis
Membrane Transport
Review
Supplemental

We will be going into greater detail on particular cell structures in this course. However, it's a good idea to get at least a general sense of the major organelles and structures of the cell. Your responsibility (for now) will only include the parts indicated below in the terminology. However, the questions will hopefully help you to read a little more in depth.

There will be no video lecture for the intro, instead you will read the openstax chapter on the cell and use the Cell Intro companion questions as a guide.

Direct link to Openstax Ch 4

Learning objectives

Know the major organelles and structures of a cell, and their function

Relevant Terminology

prokaryote - bacteria, organisms without a nucleus or organelles
eukaryote - organism with nucleus and other organelles
organelle - a membrane-bound structure
nucleus - stores DNA
cytoplasm - the region outside the nucleus (including organelles)
cytosol - the gel-like substance of the cytoplasm (not including organelles)
Ribosome - enzyme that makes polypeptides (proteins)
Mitochondria - makes ATP
Peroxisome - organelle that carries out REDOX reactions in order to detoxify.
Vesicle (and vacuoles) - sacs for storage and transport
Lysosome (rare in plants) - digestive compartment (organelle)
Cell Wall (plants, some fungi and bacteria) - rigid polysaccharide layer. Cellulose in plants. Petidoglycan (protein & saccharide)
Chloroplast (plants, some others) - photosynthesis
ER - lipid biosynthesis
Golgi apparatus - the post office of the cell, sends off proteins and lipids and other biomols to their final destinations
Cytoskeleton - fiber network for movement, contraction, transport, & structure
- microtubules
- microfilaments
- intermediate fibers
Extracellular Matrix - The mixture surrounding cells
- many fibrous glycoproteins - such as collagen
- interstitial fluid

This section is the most difficult and we will spend considerable time in class for practice. If you can't get to the next tab with membrane transport. This will make a good stopping point, but be sure to have the flow chart (or your own version) for class.

Diffusion & Osmosis Companion Questions

Learning Objectives

be able to predict the movement of solutes
Osmotic Pressure - be able to predict the initial movement of water
Tonicity - be able to predict the NET, long-term movement of water
Given water movement, be able to estimate tonicity
Permeability - given water movement, be able to determine solute permeability

Notes:

- we are assuming that one solute (ion) does not affect another. For example that Na⁺ will not affect the movement of K⁺. In reality, if the proportions are high enough, they would. However, in a typical cell, total solute concentrations are more or less equal throughout different compartments, so it we won't consider that part for these exercises.

sorry this video is old, so the quality is not as good.

Terminology

Concentration gradient
permeability / permeable / penetrating etc
diffusion
osmosis - water movement
osmotic pressure - the CURRENT (instant in time) attractive force on water, caused by the [solute]. (NOT THE SAME AS OSMOSIS)
osmolarity (not the same as osmosis, but close to osmotic pressure) = TOTAL [solute]
osmoles (Osm) - the units for solute concentration, like molarity (M), however it is generic. Osm is metric, so there are also milliOsmoles (mOsm) & microOsmoles (uOsm).
Tonicity - the long-term / net water movement - just measured in moles / molarity (M)
Hyper- / Hypo- / Iso- prefixes

Use the flow chart to help you. Draw things out! Visualize and go step by step.

Diffusion & Osmosis Flow Chart.png

The Cell 3 - Transport

Learning Objectives

Understand the different transport mechanisms
Be able to name transport proteins properly
Be able to determine permeability based on membrane protein content
know the difference between simple & facilitated
know the difference between passive & active
know the difference between leaky & gated/ regulated
integrate diffusion & osmosis with membrane transport

Terminology

Concentration gradient
permeability / permeable / penetrating etc

Diffusion and Osmosis

Membrane Transport

Protein Trafficking

Cytoskeleton

Cell Transport

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Endocytosis