Chapter 6.1 All organisms are made of cells.
Pages 110 - 114
Microscopes
· ______________ microscopes are used in the classroom today.
· Developed around ___________ AD.
· Visible light passes through an object.
· Glass ______________ enlarge the image & project it.
· _____________________ used an original version of the microscope to discover compartments in a slice of _______________ (which he called _______________).
The Cell Theory
· ______________ discovered the first cells that were actually walls of dead __________________ cells.
· Advances in technology have led to further investigation.
· ____________________ invented the light microscope & observed tiny organisms (he called _____________).
· Every organism investigated by scientists has led to the identification of _________.Led to Cell Theory.
States:
1. All living things are composed of ____________.
2. Cells are the basic unit of structure & _______________ in living things.
3. All cells come from pre-existing _________.
More on Microscopes
LM (_____________________) are useful for magnifying objects up to ______________ X their orginal size.
True or False: Much of the cell’s structure is so small that such magnification is not enough to see it.
In the 1950s, the ________________ (SEM & TEM) was invented.
Scientists can now see an object magnified ___________X.
Now can we see internal details? _____!
Micrographs
The light microscope is still useful. Why? ________________________
The ___________________ is the photo of the view through a microscope.
Noted as “LM 200X”Page 111 Fig. 6-3, Paramecium
Solve! Which microscope (SEM, TEM, LM) works best?
1. Which will examine the surface of microelectronic devices used to make CDs? __________
2. Which can look at the mitochondria in a tissue sample taken at an autopsy? ______
3. Which will help map swimming movements of plankton in an area of the ocean contaminated by an oil spill? _________P
age 111 – Know Fig. 6-2, Parts of a microscope.
Animal Cell and Plant Cell
The “mini-organs” of a cell are called ____________________.
Each has a specific job.
___________________ is the outer covering.
__________________ is the house of genetic material (____________).
___________________ is the fluid suspension of various organelles.Some of these organelles have their own membrane.Most organelles are the same, and just a few differences make them very separate!
______________Where _________ occurs (converting __________ E into __________ E stored in sugar).
______________Protects and Maintains _______
2 Major Classes of Cells
Prokaryotic
Lacks a _________
Lacks most other ______________
Bacteria and organisms of Domain _________Where is its DNA? _______________
Larger or smaller?
Eukaryotic
Has a nucleus.
Has membrane-bound organelles.
Example:________________________Larger or smaller?
Chapter 6.2 Membranes organize a cell’s activity.
I. Membrane Structure
A. Keep cell contents __________________________. For example, keep enzymes compartmentalized.
B. Regulate the ______________ of substances across the boundary, allowing only certain substances to pass.
C. Composed mostly of ___________________ & ___________________
1. like the fat molecule, but has just _____ fatty acid chains
2. “head” is a ________________________
3. “tail” is ______________________________
Hydrophilic Hydrophobic
Head Tail
4. If the tail is hydrophobic and the liquid contents of a cell are aqueous, which part of the phospholipid will be facing the cellular contents? __________________ Why? ______________________________
5. This structure allows phospholipids to form boundaries between two watery environments. In fact, a two-layer boundary is used (called a ________________________________________).
6. The phospholipid bilayer will surround an organelle or cell.
7. Because the hydrophobic _________________ are tucked away inside the membrane, they play a key role in the membrane’s function as a selective barrier.
a. nonpolar molecules (like oxygen & carbon dioxide) will pass freely
b. polar molecules (like sugars) and ____________ do not pass as easily
8. Together, the phospholipids, proteins and other membrane components form a dynamic structure.
a. True or False: Membranes are fluid rather than rigid.
b. True or False: Most proteins are “stuck” in the same position rather than freely floating in the membrane.
D. Functions of Membrane Proteins
1. Proteins are embedded in the membrane’s phospholipid bilayer.
2. Other molecules (like carbohydrates) may be attached to the bilayer, too, but proteins perform most of the membrane’s specific function.
a. Enzyme activity: Such proteins in the membrane could be ____________________, that catalyze reactions of nearby substrates.
b. Cell-to-cell recognition: Proteins help cells communicate and ___________________ each other.
c. Transport Proteins help _________________ some substances (like ______________________________) across the membrane.
d. Cell signaling: A chemical messenger binds to a membrane protein, causing it to change shape and relay the message inside the cell.
***Page 117 Fig. 6-9***
Chapter 6.3 Membranes Regulate the Traffic of Molecules
I. Diffusion
A. All particles are ___________________ randomly moving.
B. definition: Net movement of the particles of a substance from where they are ____________________ concentrated to where they are ____________________ concentrated.
1. ________________________ membrane
a. molecules can pass freely
b. no _______________________ expense
2. True or False: Since particles are constantly moving, particles will cross back and forth through the membrane constantly.
C. Equilibrium
1. “_________________________”
2. number of particles moving in one direction __________________ the number of particles moving in the opposite direction.
II. Passive Transport
A. Membranes do not allow some particles to travel across easily.
B. ____________________________________
1. some particles pass freely, others do not
a. which particles pass more easily, large or small?
b. for particles that are too big or too restricted by the hydrophobic interior membrane, a transport protein is helpful (called facilitated diffusion)
2. like a window screen – air flows freely, bugs do not!
3. in a typical cell, a few molecules diffuse freely (like ______________ and __________________________)
4. other molecules require a ____________________ to help transport
C. In ALL cases, ________________ energy is required to transport across the membrane.
D. Page 119, figure 6-12
III. Osmosis
A. Passive transport of _____________________ across a selectively permeable membrane
B. Solution with a higher concentration of solute = _______________________
Solution with a lower concentration of solute = ________________________
Which has a higher concentration of water? _______________________
C. For example, what will happen if a hypertonic sugar solution, trapped in a balloon/membrane, is placed in a container of hypotonic sugar solution? _________________________________________________________
Placed in pure water container? ____________________________________
D. Particles will continue to pass until they are in equal concentrations on both sides of the membrane. Called _____________________.
E. Animal Cells
1. Page 112, figure 6-14
2. Red blood cells look like: In hypertonic solution: In hypotonic solution:
F. Plant Cells
1. Page 121, figure 6-15B
2. Strong ___________________________ that will retain water for ________________!
3. When bathed in water, like after rainfall, cell appears __________________.
Why won’t the cell burst (like an ____________ cell)? _________________________________________________
4. When too little water is received, the plant cell membrane pulls away from the wall.
IV. Active Transport
A. A cell expends ______________________ to move molecules or ions across the membrane.
B. A specific transport protein pumps a solute across the membrane.
1. True or False: Since energy is required in active transport, the molecule is moved from higher concentration to lower concentration, like diffusion.
2. Usually, molecules are moved in this direction: ______________________________________________________________
a. uses energy provided by the cell’s __________________________
b. For example, ______________________________ (where Na+ is pumped out of the cell, K+ into the cell – against the concentration gradient)
C. Transport of LARGE molecules
1. Large molecules cannot simply pass through the membrane.
2. Must be packaged into __________________________ (membrane- bound!)
a. vesicles are membrane-bound sacs
b. vesicles specialize in moving products into, out of, and within the cell
c. For example, to move molecules out of the cell: the vesicle will package the molecule, move to the cell membrane, ___________________ with the membrane and spill its contents outside the cell. Called ______________________.
d. Taking material in requires a vesicle that buds from the membrane. Called ____________________________.
e. Even to bring in food, a membrane-bound vesicle will form. Called _______________________________.
Chapter 6.4 Cell Parts
Define each organelle in terms of its contribution to the cell and how it works.
1. Nucleus 2. Nuclear envelope 3. Nucleolus 4. Ribosomes 5. Endoplasmic Reticulum (ER) 6. Rough ER 7. Smooth ER 8. Golgi Apparatus 9. Vacuoles 10. Lysosomes 11. Chloroplasts 12. Mitochondria 13. Cytoskeleton 14. Microtubules 15. Microfilaments 16. Flagella 17. Cilia
**What is ATP?
Concept Check (p. 127 #1 – 3), using complete sentences.