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12/16/10. Objective: To understand the structure and function of the cell membrane Do Now: What is meant by “fluid mosaic” model as a description for the membrane?. Today: 1. Do Now/Sign - up for presentations Discuss/Collect Evidence for life article Cell Membrane Note

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12/16/10

  • Objective: To understand the structure and function of the cell membrane

  • Do Now:What is meant by “fluid mosaic” model as a description for the membrane?

  • Today:1. Do Now/Sign - up for presentations

  • Discuss/Collect Evidence for life article

  • Cell Membrane Note

  • Osmosis/Diffusion LABS


12/17/10

  • Objective: To understand the structure and function of the cell membrane

  • Do Now:What is diffusion? How do molecules flow?

  • Today:1. Do Now/Collect Evidence for Life Article

  • Osmosis/Diffusion LABS

  • Membrane Notes


1/3/11 – “E” day

  • Objective: To understand the structure and function of the cell membrane

  • Do Now:What is osmosis? How do cells behave in a hypotonic solution?hypertonic solution?isotonic solution?

  • Today:

  • Do Now

  • PJAS/MCSRC announcements

  • Did you hand in your diffusion lab?

  • Homework - Chapter 5 Review Handout

  • IRP Presentations:

    • Sean

    • Nick M.

    • Sarah

    • Rose

    • Bjay

    • Stephen

MCSRC Meeting WEDNESDAY – Jan. 5th

D20 Mrs. Biondo

Tomorrow:

Lindsay

Patrick

Matt B.

Jeremy


1/3/11 – “E” day

  • Objective: To understand the structure and function of the cell membrane

  • Do Now:What is osmosis? How do cells behave in a hypotonic solution?hypertonic solution?isotonic solution?

  • Today:

  • Do Now

  • PJAS/MCSRC announcements

  • Did you hand in your diffusion lab?

  • Homework - Chapter 5 Review Handout

  • IRP Presentations:

    • Marissa

    • Suzie

    • Sang

Tomorrow:

Jess Q.

Bea

Jen

Stephanie

Paul

Andy

MCSRC Meeting WEDNESDAY – Jan. 5th

D20 Mrs. Biondo


1/6/11 – “B” day

  • Objective: To understand the structure and function of the cell membrane

  • Do Now:What is active transport across a membrane? Passive transport?

  • Today:

  • Do Now

  • Complete IRP presentations

  • Complete Membrane Notes

  • Value of Villi Activity

  • Homework - Chapter 5 Review Handout


1/10/11 – “D” day

  • Objective: To understand the function of enzymes in metabolism

  • Do Now:What is ATP, what is it used for?

Today:

Do Now

Did you try the Enzyme Packet?

Go over Enzyme Packet

Review


Hypertonic solution

Hypotonic solution

Isotonic solution

H2O

H2O

H2O

H2O

Animalcell

(3) Shriveled

(2) Lysed

(1) Normal

Plasmamembrane

H2O

H2O

H2O

H2O

Plantcell

(6) Shriveled (plasmolyzed)

(5) Turgid

(4) Flaccid


MEMBRANE STRUCTURE AND FUNCTION

  • 5.10 Membranes organize the chemical activities of cells

    • Membranes

      • Provide structural order for metabolism


Outside of cell

Cytoplasm

TEM 200,000 

  • The plasma membrane of the cell is selectively permeable

    • Controlling the flow of substances into or out of the cell

Figure 5.10


CH3

Hydrophilic head

+

N

CH2

CH3

CH3

CH2

Phosphategroup

O

P

O–

O

O

CH

CH2

CH2

O

O

O

O

C

C

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

Symbol

CH

CH2

CH

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH2

CH3

CH3

Hydrophobic tails

  • 5.11 Membrane phospholipids form a bilayer

    • Phospholipids

      • Have a hydrophilic head and two hydrophobic tails

        • Fatty Acid chains!

      • Are the main structural components of membranes

Figure 5.11A


Water

Hydrophilicheads

Hydrophobictails

Water

  • Phospholipids form a two-layer sheet

    • Called a phospholipid bilayer, with the heads facing outward and the tails facing inward

Figure 5.11B


Fibers of the extracellular matrix

Carbohydrate(of glycoprotein)

Glycoprotein

Glycolipid

Plasmamembrane

Phospholipid

Proteins

Microfilamentsof cytoskeleton

Cholesterol

Cytoplasm

  • 5.12 The membrane is a fluid mosaic of phospholipids and proteins

    • A membrane is a fluid mosaic

      • With proteins and other molecules embedded in a phospholipid bilayer

Figure 5.12


Fibers of the extracellular matrix

Carbohydrate(of glycoprotein)

Glycoprotein

Glycolipid

Plasmamembrane

Phospholipid

Proteins

Cholesterol

Microfilamentsof cytoskeleton

Cytoplasm


  • 5.13 Proteins make the membrane a mosaic of function

    • Many membrane proteins

      • Function as enzymes (biological catalysts – speed up reactions)

Figure 5.13A


Messenger molecule

Receptor

Activatedmolecule

  • Other membrane proteins

    • Function as receptors for chemical messages from other cells

Figure 5.13B


ATP

  • Membrane proteins also function in transport

    • Moving substances across the membrane

Figure 5.13C


Molecules of dye

Membrane

Equilibrium

Equilibrium

  • 5.14 Passive transport is diffusion across a membrane

    • In passive transport, substances diffuse through membranes without work by the cell

      • Spreading from areas of high concentration to areas of low concentration

Figure 5.14A

Figure 5.14B


  • Small nonpolar molecules such as O2 and CO2

    • Diffuse easily across the phospholipid bilayer of a membrane


Solutemolecule

Transportprotein

  • 5.15 Transport proteins may facilitate diffusion across membranes

    • Many kinds of molecules

      • Do not diffuse freely across membranes

    • For these molecules, transport proteins

      • Provide passage across membranes through a process called facilitated diffusion

Figure 5.15


1/7/11 – “C” day

  • Objective: To understand the structure and function of the cell membrane

  • Do Now:What would likely happen to an animal cell placed in a hypotonic solution? A hypertonic solution? Why are animal cells different?

  • Today:

  • Do Now/Homework Check - Chapter 5 Review Handout

  • Complete Membrane Notes

  • Value of Villi Activity

  • Enzymes and Metabolism POGIL


Equalconcentrationof solute

Higherconcentrationof solute

Lowerconcentrationof solute

H2O

Solutemolecule

Selectivelypermeablemembrane

Watermolecule

Solute molecule with

cluster of water molecules

Net flow of water

  • 5.16 Osmosis is the diffusion of water across a membrane

    • In osmosis

      • Water travels from a solution of lower solute concentration to one of higher solute concentration

Figure 5.16


Hypertonic solution

Hypotonic solution

Isotonic solution

H2O

H2O

H2O

H2O

Animalcell

(3) Shriveled

(2) Lysed

(1) Normal

Plasmamembrane

H2O

H2O

H2O

H2O

Plantcell

(6) Shriveled (plasmolyzed)

(5) Turgid

(4) Flaccid

  • 5.17 Water balance between cells and their surroundings is crucial to organisms

    • Osmosis causes cells to shrink in hypertonic solutions

      • And swell in hypotonic solutions

    • In isotonic solutions

      • Animal cells are normal, but plant cells are limp

Figure 5.17


  • The control of water balance

    • Is called osmoregulation


Transportprotein

P

P

P

Phosphatedetaches

Proteinchanges shape

ATP

Solute

ADP

Transport

1

Solute binding

2

Phosphorylation

3

4

Protein reversion

  • 5.18 Cells expend energy for active transport

    • Transport proteins can move solutes against a concentration gradient

      • Through active transport, which requires ATP

Figure 5.18


Fluid outside cell

Vesicle

Protein

Cytoplasm

  • 5.19 Exocytosis and endocytosis transport large molecules

    • To move large molecules or particles through a membrane

      • A vesicle may fuse with the membrane and expel its contents (exocytosis)

Figure 5.19A


Vesicle forming

  • Membranes may fold inward

    • Enclosing material from the outside (endocytosis)

Figure 5.19B


Plasma membrane

Food being ingested

Pseudopodium of amoeba

Material bound to receptor proteins

PIT

TEM 96,500 

TEM 54,000

Cytoplasm

LM 230

Phagocytosis

Receptor-mediated endocytosis

Pinocytosis

  • Endocytosis can occur in three ways

    • Phagocytosis

    • Pinocytosis

    • Receptor-mediated endocytosis

Figure 5.19C


Phospholipid outer layer

LDL particle

Vesicle

Cholesterol

Protein

Plasmamembrane

Receptorprotein

Cytoplasm

CONNECTION

  • 5.20 Faulty membranes can overload the blood with cholesterol

    • Harmful levels of cholesterol

      • Can accumulate in the blood if membranes lack cholesterol receptors

Figure 5.20


  • 5.21 Chloroplasts and mitochondria make energy available for cellular work

    • Enzymes are central to the processes that make energy available to the cell


  • Chloroplasts carry out photosynthesis

    • Using solar energy to produce glucose and oxygen from carbon dioxide and water

  • Mitochondria consume oxygen in cellular respiration

    • Using the energy stored in glucose to make ATP


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