Day 1-1 (4A) A lab technician needs to determine whether cells in a test tube are prokaryotic or eukaryotic. The technician has several dyes she could use to stain the cells. Four of the dyes are described in the table below:

Dye Test Acridine orange Stains DNA and RNA Osmium tetroxide Stains lipids Eosin Stains cell cytoplasm Nile blue Stains cell nuclei

Which dye could the technician use to determine whether the cells are prokaryotic or eukaryotic? F acridine orange G osmium tetroxide H eosin J Nile blue Day 1-2 (4B) Which of the following pairs matches a cell organelle with its function? F chloroplast—movement G nucleus—cell regulation H vacuole—energy production J mitochondrion—photosynthesis

The Plasma Membrane = The Plasma Membrane = The Cell Membrane The Cell Membrane

The Most Important Job…

Maintaining HOMEOSTASIS

•Homeostasis = internal balance

•All living cells must maintain balance

How does it maintain homeostasis?

The plasma membrane controls what goes in and out

•Like a good bouncer

How does it maintain homeostasis?

c). allow waste and other products to leave the cell.

b). remove excess amounts of these nutrients when levels get so high that they are harmful.

a). allow a steady supply of water, glucose, amino acids, and lipids to come into the cell.

Selectively Permeable Membrane

Allows some substances to cross and not others

H2Osugar

lipids

salt

waste

• Small uncharged polar particles may pass

• Large uncharged polar molecules and ions

cannot pass

Selectively Permeable Membrane

Structure Of The Plasma Membrane

Structure Of The Plasma Membrane

Phospholipid bilayer

•2 layers of lipids

•Phosphate head - Hydrophilic - Polar

•Fatty acid tail - Hydrophobic - Non polar

• To make the cell membrane, phospholipids come together to make two layers

• Which option makes the most sense? WHY?

A B C

Structure Of The Plasma Membrane

Membrane Proteins

•Transport channels

•Chemical receptors

•Cell to cell communication

Structure Of The Plasma Membrane

Structure Of The Plasma Membrane

Cholesterol

•Keep the phospholipids spaced apart

•Keeps the membrane fluid/flexible

Structure Of The Plasma Membrane

Surface Carbohydrates

•Cell signaling

•Cell recognition

•Cell adhesion

Show me…part of your membrane

Which part forms the bilayer?

Which part helps with transport?

Which part keeps the membrane fluid?

Which part functions in cell signaling?

Eww…That is one smelly balloon

How do the smells get out of the balloons?

The balloon is a semipermeable membrane

Molecules small enough to fit through the “holes” in the balloon diffuse through the

membrane

Remember Smelly Balloons?

•Just like the balloon the cell membrane is selectively or semi permeable

•This means only some things can diffuse through the cell membrane

• Now lets talk more about diffusion…

Types of TransportTwo types of cellular transport:

Passive

Active

Passive TransportPassive Transport -Requires -Requires NO EnergyNO Energy--Molecules move from an area of HIGH concentration to an area of LOW concentrationMolecules move from an area of HIGH concentration to an area of LOW concentration-With the concentration gradient-With the concentration gradient

-Diffusion-Diffusion-Facilitated Diffusion-Facilitated Diffusion-Osmosis-Osmosis

Important Vocabulary

Solute - The solid substance that is dissolved in a solvent.

Solvent - The liquid substance in which the solute is dissolved.

Solution - The mixture of two or more substances (solute and solvent) in which

the molecules of the substances are evenly distributed.

DiffusionDiffusionThe passive movement of molecules from an area of high concentration to an area of low concentration

Fun With Food ColoringFun With Food Coloring

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html

Facilitated DiffusionDiffusion where a protein carrier molecule

or channel helps transport molecules across the membrane

OsmosisOsmosisThe diffusion of water across a selectively permeable membrane

•Water moves from an area of high water concentration to an area of low water concentration

•Water moves to where there are MORE solute molecules

Where are the solute ions more concentrated?

Which way will theWhich way will the Cl- Cl- andand Na+Na+ ions move?ions move?

http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html

1)1) Hypertonic solutionHypertonic solution2)2) Hypotonic solution Hypotonic solution 3)3) Isotonic solution Isotonic solution

OsmosisOsmosis occurs in 3 types of solutions.

Hypertonic EnvironmentHypertonic Environment

• An environment with a more solute concentration compared to another

97% NaCl3% H2O

3% NaCl97% H2O

OsmosisOsmosis = The diffusion of water across a membrane.

Water moves

OUT

Hypertonic EnvironmentCell will Shrink

Hypotonic EnvironmentHypotonic Environment

• An environment with a less solute concentration compared to another

3% NaCl97% H2O

97% NaCl3% H2O

OsmosisOsmosis = The diffusion of water across a membrane.

Water moves

IN

Hypotonic Environment Cell will Lyse (Swell)

Isotonic EnvironmentIsotonic Environment

• An environment with equal solute concentration compared to another

3% NaCl97% H2O

3% NaCl97% H2O

OsmosisOsmosis = The diffusion of water across a membrane.

Water moves

IN & OUT

Isotonic Environment Cell will Stay the same

Which way will the water diffuse?What type of solution is in each beaker? IsotonicIsotonicHypertonicHypertonic HypotonicHypotonic

Gummy Bear Lab - Day 1

Not for eating!

Okay…maybe when we’re finished

Types of TransportTwo types of cellular transport:

Passive

Active

Active TransportActive Transport -Requires -Requires EnergyEnergy--Molecules move from an area of LOW concentration to an area of HIGH concentrationMolecules move from an area of LOW concentration to an area of HIGH concentration-Against the concentration gradient-Against the concentration gradient

-Endocytosis-Endocytosis-Exocytosis-Exocytosis-Protein Pump-Protein Pump

Endocytosis and Exocytosis

Exocytosis and Endocytosis are ways a cell can pass proteins out of or into the cell.

Exocytosis-a membrane bound vesicle, fuses with the membrane, and releases its contents outside the cell

Endoocytosis-the cell membrane engulfs (“eats”) molecules, and takes them into the cell

Protein Pump

• Use energy to pump ions from

low concentratio

n to high concentratio

n