Chapter 3 and 4:  Cell Structure, Organelles and the Environment

 

Using your vocabulary words, make notecards/flashcards that you can use outside of class to study. 

 

Chapter 3

Chapter 4

Work on your Directed Reading in class every chance you get.  Remember that I will assist you on the harder questions.  This assignment is due the day we take the test on this chapter.  Use the information in this assignment as a study guide for your test.

This study guide is to help you study for your test.  It should not be the only item you use to study w hen preparing for the test.  Remember to complete your Directed Reading for every chapter along with writing your vocabulary words on notecards to help you remember them.  And always remember to listen carefully in lecture because all of the information in this study guide will be covered.

 

The Living Cell Worksheet 

 

 

Chapter 3 & 4 Coloring Lab 

 

I.      Section1: Looking at Cells

A.   Microscopes are used to enlarge our view of the cell to see features clearly.

1.    Light Microscope – light is passed through lenses to produce an enlarged image

 

 

 

2.    Electron Microscope – beams of electrons are used to enlarge the image, has higher resolution than light microscopes

a)    Transmission Electron Microscope (TEM) – e- beams sent thorough thin slice of specimen stained with metal ions

 

 

b)    Scanning Electron Microscope (SEM) - e- beams Focused on object coated with metal ions – forms 3d picture

 

 

3.    Scanning Tunneling Microscope – creates a 3D image of objects as small as the atom

 

 

4.    Microscope terminology:

a)    Magnification – ability to make an image larger

b)    Resolution – measure of image clarity (how clean the image is)

c)    The higher the resolution the lower the resolution

 

 

II.    Section 2: Cell Features

A.   Cell Theory

1.    All living things are made of cells

2.    Cells are the basic units of an organism, & the smallest unit of life.

3.    All cells come from other cells

 

 

 

 

III.   Section 2: Prokaryotic vs. Eukaryotic Cells

 

 

A.   Prokaryotic Cells

1.    Lack a nucleus and lack distinct organelles (structure within the cell with a specialized function)

2.     Modern prokaryotic cells are bacteria

3.     All prokaryotic cells are single celled organisms (dogs/poodles thing)

4.    Have circular DNA

B.   Eukaryotic cells

1.    Have a nucleus and distinct organelles

2.    Found in single and multi-celled organisms

3.    Includes animal, plant, protist, and fungi cells

 

     

 

IV.  Section 2: Cell Membrane (aka plasma membrane, aka phospholipid bilayer)

 

 

A.   Contains the cytoplasm and organelles

B.   Fluid in texture, like a soap bubble

C.   Forms a semi-permeable barrier (lets only certain things in and out)

 

 

D.   Made of phospholipids (each molecule has a phosphate group and two fatty acids) arranged in a double layer called the lipid bilayer (pg 59 fig 3-9);

1.     polar “head” (phosphate groups) of the molecules are hydrophilic (“water loving” - attracted to the water) and therefore turn to the outside of the membrane (toward the outside and inside of the cell),

2.    non-polar “tails” (fatty acids) are hydrophobic (fear water – repelled by water) and therefore turn toward the inside of the membrane (away from the inside and outside of the cell.

E.   Proteins are embedded in the lipid bilayer (pg 60, fig 3-10)

1.    Marker proteins - helps cells identify each other

2.    Receptor proteins - bind to specific substances

3.    Transport proteins - move specific things into and out of the cell

4.    Enzymes - involved in biochemical reactions

V.    Section 3: Animal Cell Organelles

A.   Cell Membrane - encloses the cell, made of a “phospholipid bilayer”

B.   Nucleus - houses the DNA (aka genes) for the cell (aka control center of the cell)

C.   Nucleolus - found within the nucleus, produces ribosomes (ribosomal DNA)

D.   Mitochondria - tubelike with inner membrane, produces energy, “powerhouse of the cell”

E.   Endoplasmic Reticulum (ER) - system of membranes that move substances through the cell

1.    Rough ER - has ribosomes attached, site of protein synthesis; “highway”; moves proteins made for export by cell membrane

2.    Smooth ER - does not have ribosomes attached; moves mostly fats

F.    Ribosomes -pebble shaped found on ER, location of protein production for use by the cell

G.   Cytoskeleton - provides structure for the cell

1.    Microtubules - long hollow tubes that provide support for the cell; make up the core of flagella and cilia

2.    Microfilaments - thin stringy fibers that provide support for the cell

H.   Golgi Apparatus - set of flat membranous sacs, acts as a packing and distribution center

I.      Lysosomes - small spherical sacs containing digestive enzymes

J.    Vesicle - small membranous sac, transports substances (ex. Food, H2O, waste)

K.   Centrioles – pair of cylinder-shaped bodies found in the centrosome of most eukaryotic organisms other than plants. During cell division (both mitosis and meiosis), the centrioles move apart to help form the spindle, which then distributes the chromosomes in the dividing cell

L.    Centrosome - small region of cytoplasm adjacent to the nucleus that contains the centrioles and serves to organize microtubules

 

 

VI.  Section 3: Plant Cell Organelles

A.   All of the organelles found in animal cells (minus Lysosomes and centrioles) PLUS…

B.   Cell Wall - surrounds the cell membrane, provides structure

C.   Chloroplasts - green button shaped, location of photosynthesis

D.   Central Vacuole - takes up much of the cell’s volume, stores water

 

 

 

Plant and Animal Cell Comparison

Plants Only	Plants and Animals	Animals Only
Cell Wall	Cell Membrane	Lysosomes
Central Vacuole	Mitochondria*	Centrioles
Chloroplast*	Rough Endoplasmic Reticulum
	Smooth Endoplasmic Reticulum
	Nucleus
	Ribosomes
	Cytoskeleton
	Golgi Apparatus

*Chloroplasts and mitochondria have their own DNA and are able to copy themselves making them unique!

 

 

VII.       Passive Transport

A.  Movement of substances across the cell membrane that does not require energy (moving WITH the gradient)

B.  Concentration gradient - difference in concentration of a substance across space

C.  Equilibrium - occurs when the concentration of a substance is equal across space

D.  Types of Passive Transport

1.    Diffusion - movement of a substance from an area of higher concentration to an area of lower concentration that is caused by the random movement of the particles of that substance

 

 

 

Diffusion is…

 

Why we can smell things	Why the whole spoon gets hot when it's only half in the tea	Why smoke spreads to fill a whole room

 

 

2.    Osmosis - diffusion of water, can occur in three patterns of movement

 

 

a)    Water moves OUT of the cell - occurs when the cell is in a hypertonic environment - the environment contains a higher level of dissolved substances (and therefore a lower concentration of water) than the cytoplasm of the cell therefore water moves out of the cell to achieve a balance

b)    Water moves IN to the cell - occurs when the cell is on a hypotonic environment - the environment contains a lower level of dissolved substances (and therefore a higher concentration of water)  than the cytoplasm of the cell therefore water moves into the cell to achieve a balance

c)     No NET movement of water - occurs when the cell is in a isotonic environment - the environment contains an equal level of dissolved substances (and therefore an equal concentration of water) than the cytoplasm of the cell therefore water molecules  move equally into and out of the cell to maintain a balance    

 

         

                                  

3.    Facilitated Diffusion - transportation of substances across a cell membrane with the help of carrier proteins; only works when moving down a concentration gradient

 

 

a)     Carrier proteins bind a specific type of and carry the solute to the other side of the membrane. The carrier then discharges the solute and reorients in the membrane to its original state. Typically, a given carrier will transport only a small group of related molecules

b)    Ion Channels do not bind the solute, but are like hydrophilic pores through the membrane that open and allow certain types of solutes, usually inorganic ions, to pass through. In general, channels are quite and are quite a bit faster than carrier proteins. Additionally, many channels contain a "gate" which is functions to control the channel's permeability. When the gate is open, the channel transports, and when the gate is closed, the channel is closed.

 

 

 

VIII.     Active Transport

A.  Movement of substances across the cell membrane that does require energy (moving AGAINST the gradient, aka up the concentration gradient)

B.  Types of Active Transport

1.    Endocytosis - movement of substances into the cell by engulfing it in a vesicle (pouch)

 

 

a)     Phagocytosis - the cell membrane folds around the molecule or substance, isolating it for later use in a vacuole called a phagosome. (Phagocytosis is literally translated as "cell eating.")

b)    Pinocytosis – the cell membrane folds around the molecule or substance, and it is dissolved into the interior of the cell. Molecules such as proteins and other water-soluble substances are ingested this way. (Pinocytosis is literally translated as "cell drinking.")

 

 

2.    Exocytosis - movement of substances out of the cell by expelling it from a vesicle (pouch)

 

 

 

3.    Sodium – Potassium Pump  - Transport of 3 sodium (Na+) ions out of the cell and 2 potassium (K+)  ions into the cell.  Sodium ions are usually more concentrated outside of the cell and potassium is usually more concentrated inside the cell; therefore the movement is against the gradient.  Energy for this is supplied by ATP, often this pump uses much of the energy produced by the cell. 

 

 

a)    Steps in the Sodium-Potassium Pump:

(1)  Three sodium ions inside the cell bind to the pump.  Because energy is needed a phosphate group from ATP also binds to the pump.

(2)  The pump changes shape, enclosing the Na+

(3)  The pump changes again to release the Na+ on the outside of the cell

(4)  The open pump binds to 2 K+

(5)  The phosphate group is released allowing the pump to close

(6)  The pump changes and two K+ are released inside the cell

 

 

 

 

 

The Living Cell

 

The Living Cell Worksheet