Download Chapter 3: Cells KEY….59 points

Chapter 3: Cells KEY….59 points
Focus on Wellness…DID YOU KNOW? (Pages 48 and 70) 1 point each = 2 points
1. What are phytochemicals? _plant chemicals thought to be beneficial in offsetting cancer and
heart disease risks_______________________________________________________________
2. What are some dietary changes you could make that would increase your intake of helpful
phytochemicals?
_consume more plant foods; reduce intake of just meat-and-potato type of diets_____________
I. A Generalized View of the Cell 1 point each = 3 points
OBJ: Name and describe the three main parts of a cell.
1. _plasma membrane: flexible outer layer separating cell’s internal environment from its external
environment; regulates what flows in and out_________________________________________
2. _cytoplasm: all cellular content inside plasma membrane; excludes nucleus_________________
3. _nucleus: control center because it contains genes that have code for all cellular activities and
structures______________________________________________________________________
CHECKPOINT: 2 points ; 2/3 point each
1. What are the general functions of the three main parts of a cell?
_plasma: regulate what goes in and out______________________________________________
_cytoplasm: contains cytosol with dissolved solutes and suspended particles for cell use;
suspends organelles within the cell__________________________________________________
_nucleus: control center of the cell; directs all activities and structure building_______________
II. The Plasma Membrane ¼ point each = 4 ¾ points
OBJ: Describe the structure and functions of the plasma membrane.
1. Explain the functions of the plasma membrane.
_sturdy flexible barrier; controls what enters and leaves; enables cells to recognize other cells as
same or foreign__________________________________________________________________
2. Describe the structure of the plasma membrane. _phospholipids, cholesterol, and glycoproteins
3. Name and describe the two types of glycoproteins found in the plasma membrane. _ two types:
integral proteins- extend through plasma membrane, and peripheral proteins- loosely attached
to interior and exterior of plasma membrane__________________________________________
4. Selective permeability:
Lipid bilayer is permeable to:
a. _water____________________
b. _most lipid-soluble molecules_
Examples: _fatty acids_________________
_fat-soluble vitamins_________
_steroids__________________
_oxygen___________________
_carbon dioxide_____________
Lipid bilayer is not permeable to:
a. _ions____________________________
b. _charged particles or polar molecules_
Examples: _glucose____________________
_amino acids_________________
Channels are formed by _integral proteins______________________________________
Transporters change shape as they _move substances from one side to other__________
5. Recognition:
a. Receptors recognize and bind to specific molecules
Examples: _hormones_______________________
b. Enzymes _speed up chemical reactions_________
c. Cell identity markers _identify same cells (during tissue formation) or foreign cells
(danger)_________________________________________________________________
11 ¾ points possible
III. Transport Across the Plasma Membrane ¼ point each = 2 ¼ points
OBJ: Describe the processes that transport substances across the plasma membrane.
1. Fluids- _~60_% of the average body
a. Intracellular fluid- _ICF_- _in cytosol_
b. Extracellular fluid- _ECF___________
(1) _interstitial_- _in between cells of tissues________________________________________
(2) _plasma___- _in blood vessels_________________________________________________
(3) _lymph____- _in lymphatic vessels_____________________________________________
2. Concentration
a. _amount of solutes in solution___________________________________________________
b. Concentration Gradient- _difference in concentration between two areas________________
3. Practice: ½ point
97% H2O
95% H2O
Will move high to low; water; passive transport known as osmosis until
equilibrium is reached (isotonic)
A. Passive Processes
1. Diffusion: The Principle ¼ point each = 1 point
a. _high to low; no energy required__________________________________________
b. Diffusion defined:
-Substance moves due to kinetic energy
-Movement from high concentration to low concentration
-Movement of more molecules in one direction is called net diffusion
-Movement ‘down the concentration gradient’
-Continues until equilibrium is reached
SIMPLE DIFFUSION
_movement of materials through bilayer; important exchange of gases; absorption of
liquids and release of some wastes: O2, CO2, N2, fatty acids, steroids, fat-soluble
vitamins [A, D, E, and K], glycerol, small alcohols, NH3, H2O, and Urea [polar]__________
_move materials through often gated channels (integral proteins): K+, Cl-, Na+, and Ca+__
FACILITATED DIFFUSION
_move through integral proteins; substance binds to specific transporters [these change
shape]: glucose, fructose, galactose, urea, some vitamins_________________________
Figure 3.3, page 51:
1 point
1. How does simple diffusion differ from facilitated diffusion? _simple substances cross
membrane through lipid bilayer; facilitated ion channels or carriers involved______________
2. Osmosis ¼ point each = ¾ point
a. _movement of water across a selectively permeable membrane from an area of high
concentration of H2O to area of low concentration of H2O, no energy required_______
b. Practice:
Start of experiment: Semi-permeable tube (to water) contains 20% sucrose
immersed in 100% water. Arrows moving in show start of osmosis.
1. What substance is moving into the tube? _water_________________________
2. Is it moving ‘up the concentration gradient’ or ‘down the concentration
gradient’? _’down the concentration gradient’__________________________
5 ½ points possible
2
At equilibrium: ¼ point each = ¾ point
1. Which solution has increased in volume, the sucrose in the tube or the water in
the beaker? _sucrose in tube________________________________________
2. What is moving up the tube? _solution of sucrose and water______________
At start of experiment
At equilibrium
Figure 3.7, page 53:
1 point
1. Will the fluid level in the tube continue to rise until concentrations are the same in the beaker
and in the tube? _no, water concentration can never be the same because the beaker always
contains 100% pure water and the tube contains a solution that is less than 100% water______
¼ point each = 1 ½ points
c. Osmotic pressure: _pressure exerted on membrane because solute particles cannot
cross membrane; depends on concentration of solute concentration: high solute concentration = higher
osmotic pressure; low solute concentration = lower osmotic pressure_____________________________
(1) Isotonic solution: _concentration equal__________________________________
(2) Hypotonic solution: _concentration of water higher outside_________________
Condition of bursting red blood cells known as: _hemolysis__________________
(3) Hypertonic solution: _concentration of water higher inside__________________
Condition of shrinkage of red blood cells known as: _crenation_______________
Crenation
Normal
Hemolysis
Figure 3.8, page 54:
1 point
Look over and study Figure 3.8 on page 54, then answer the following question:
1. Will a 2 percent solution of NaCl cause hemolysis or crenation in red blood cells (RBCs)? Justify
your answer by explaining how you derived it.
_2% solution of NaCl will cause crenation of RBCs because it is hypertonic; water will move out
of RBCs_______________________________________________________________________
4 ¼ points possible
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B. Active Processes ¼ point each = 2 points
1. Active Transport
a. _transport materials across membrane from low to high concentration; ‘up the
concentration gradient’____________________________________________________
b. _requires the use of energy______________________________________________
- Comes from splitting of _ATP molecule____________________________________
- Changes shape of _transporter molecules_, called a _pump_
- Transports ions: _Na+, K+, H+, Ca2+, I-, and Cl-_____________
- _40%_ of a cell’s ATP expended on active transport
What drug can be lethal to ATP production? _cyanide_________
Figure 3.9, page 55: 1 point each = 2 points
Look at Figure 3.9 on page 55 and read over the section on Active Transport on page 55 in your
textbook.
1. Explain how the sodium- potassium pump works. _ sodium-potassium pump expels sodium (3)
from cell and brings in potassium (2) and acts as an enzyme to split ATP____________________
2. What is the role of ATP in the operation of the sodium-potassium pump? _ ATP adds a
phosphate group to the pump protein, which changes the pump’s three-dimensional shape ___
2. Transport in Vesicles ¼ point each = 2 ¾ points
a. _vesicles_: small sacs formed by budding off of membranes
b. Functions:
(1) _Transport substances within the cell from one structure to another______________
(2) _Take in substances from ECF and transport substances out to ECF_______________
c. Two main types of vesicular transport: _endocytosis_ and _exocytosis_
ENDOCYTOSIS
_materials moved into cell; capturing substance or particle from outside the cell by
engulfing it within membrane folds from the cell membrane and releasing it into cytosol
Two types of endocytosis:
1. Phagocytosis: _”cellular eating”____________________________________________
(1) Attachment: _ Particles bind to plasma membrane receptors________________
(2) Phagosome formation: _Projections called pseudopods extend surround
particles and portions of the membrane fuse to form a vesicle; extensions of the
plasma membrane and cytoplasm; pseudopods vesicle formed called a
phagosome________________________________________________________
(3) Phagosome-lysosome fusion: _ Phagosome enters the cell, fuses with lysosomes
(4) Digestion: _ Lysosome enzymes break down phagosome’s contents; any
undigested content remains in the phagosome, now called a residual body____
What types of cells does this only occur in? _phagocytes (certain white blood cells and
macrophages)_________________
2. Bulk-phase Endocytosis: _”cellular drinking” [pinocytosis]______________________
(1) _plasma membrane folds inwards_, forms pinocytotic vesicle that pulls in
_tiny droplets of ECF containing dissolved substances_ to be surrounded
(2) Vesicles _detaches or “pinches off”_ of plasma membrane enter _cytosol_
(3) Vesicles fuse with _lysosome_, and then _enzymes_degrade engulfed solutes
(4) Degraded solutes, like _amino acids_ and _fatty acids_ leave lysosome to be used
elsewhere in the cell
6 ¾ points possible
4
EXOCYTOSIS
¼ point each = 1 point
_materials removed from cell; process of vesicles fusing with the plasma membrane and
secretes their contents to the outside of the cell________________________________
Do all cells carry out exocytosis? _yes_______________
Exocytosis is most important in these two types of cells:
(1) _secretory cells________________________
Release digestive enzymes, hormones, mucus, and other secretions
(2) _nervous cells_________________________
Releases neurotransmitters
CHECKPOINT:
2 points
1. What is the key difference between passive and active transport? _passive  high to low
concentration; needs no energy/ active low to high concentration; needs energy___________
IV. Cytoplasm ¼ point each = 2 ¼ points
OBJ: Describe the structure and Functions of cytoplasm, cytosol, and organelles.
1. Cytoplasm defined: _everything inside plasma membrane excluding nucleus ________________
A. Cytosol
1. Cytosol defined: _ everything inside plasma membrane excluding nucleus and membranebound organelles________________________________________________________________
2. What is cytosol composed of? _ 75%-90% of cytosol is water, the rest is composed of
dissolved solutes and suspended particles ____________________________________________
3. What do the chemical reactions that occur in the cytosol help the cell with? _ Maintain cell
structure and enable cell growth____________________________________________________
CYTOSKELETON
a. Extends throughout cytosol
b. Network of three different types of protein filaments:
– _microfilaments_____________________________
– _intermediate filaments______________________
– _microtubules______________________________
c. Microfilament functions:
– Provide mechanical support and help generate movement
– Anchor cytoskeleton to integral proteins
– Provide support for microvilli
d. Microvilli functions:
– Muscle contractions
– Cell division
– Cell locomotion
e. Intermediate filaments functions:
– Found in parts of cells subjected to tension (stretching)
– Hold organelles in place
– Attach cells to one another
f. Microtubules functions:
– Help determine cell shape
– Function as transport system for organelle movement
– Secretory vesicles
– Migration of chromosomes
– Create movement of cilia and flagella
5 ¼ points possible
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B. Organelles ¼ point each = 3 ½ points
Label the lettered organelles on the diagram pictured below :
a. smooth ER
b. GOLGI COMPLEX
c. MITOCHONDRIA
d. ROUGH ER
e. RIBOSOMES
f. CILIA
g. MICROVILLI
h. CENTRIOLES
i. NUCLEOLUS
j. LYSOSOME
k. PLASMA MEMBRANE
l. PEROXISOME
m. NUCLEUS
n. CYTOSOL/CYTOPLASM
Describe briefly the function of each organelle listed below: ¼ point each = 2 ¾ points
1. Centrosome: role in cell division
2. Cilia: motile projections; increase surface area
3. Flagella: motile projections
4. Ribosomes: synthesize proteins
5. Rough Endoplasmic Reticulum: production of proteins for export
6. Smooth Endoplasmic Reticulum: site of lipid synthesis
7. Golgi Complex: sorts, modifies, packages proteins & lipids; forms lysosomes
8. Lysosomes: vesicles with digestive enzymes
9. Peroxisomes: vesicles with enzymes to detoxify drugs, alcohol, harmful substances; hydrogen
peroxide
10. Proteasomes: vesicles that dispose of dying cells
11. Mitochondria: site of ATP production
CHECKPOINT: 2 points each = 4 points total
1. What does cytoplasm have that cytosol does not? _includes membrane-bound organelles___
2. What is an organelle? _specialized structures inside cells that have specific shapes and functions
V. Nucleus ¼ point each = 1 ¾ points
OBJ: Describe the structure and functions of the nucleus.
Label the lettered organelles on the diagram pictured below :
A. NUCLEAR ENVELOPE
B. CHROMATIN
C. NUCLEOLUS
D. NUCLEAR PORES
E. ROUGH ER
F. POLYRIBOSOMES
Describe briefly the function of nucleus below: controls cellular structure, directs cellular activity,
produces ribosomes in nucleoli
CHECKPOINT: 2 points
1. Why is the nucleus so important in the life of a cell? _because it contains the genes that control
cellular activity and cellular structure and pass on hereditary traits_______________________
12 ¼ points possible
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VI. Gene Action: Protein Synthesis ¼ point each = 2 points
OBJ: Outline the sequence of events involved in protein synthesis.
1. What do the proteins made during protein synthesis determine for cells and organisms?
Physical and chemical characteristics of cells/organisms
2. Where in the cell and on what is the code for making proteins stored?
Genes on DNA in cell nucleus
3. Define protein synthesis.
The making of protein molecules through transcription and translation processes
A. Transcription
1. Where does this process take place in the cell?
Cell nucleus
2. What enzyme catalyzes this process?
RNA polymerase
3. Compare the three types of RNA (you may need to do some research) in the chart below:
0.04 points per box
B. Translation
1. What happens during translation?
Process in which mRNA associates with ribosomes and directs synthesis of protein by
converting the sequence of nucleotides in mRNA into a specific sequence of amino acids
2. Label and color (first fill in the color key on the lower right side) the chart below:
¼ point colored in; ½ point molecule colored in; 1 point each step 1 &2 = 3 points
5 ¼ points possible
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¼ point each = 1 ½ points
VII. Somatic Cell Division ¼ point each = 1 ½ points
OBJ: Discuss the stages, events, and significance of somatic cell division.
1. Why are body cells replaced? _because they become damaged, diseased, or worn out________
A. Interphase
1. What is the first step? _nucleus replicates DNA_____________________________________
2. What else occurs during interphase? _cell manufactures additional organelles and cytosolic
components in anticipation of cell division_________________________________________
B. Mitotic Phase
1. What becomes visible during this phase? _chromosomes_____________________________
1. Nuclear Division: Mitosis
a. Four stages:
(1) _prophase____________________
- _chromatin fibers condense and shorten into chromosomes______________________
- _chromosomes become chromatids__________________________________________
- _centromeres hold chromatids together______________________________________
- _mitotic spindles form_____________________________________________________
(2) _metaphase___________________
- _centromeres align along metaphase plate____________________________________
(3) _anaphase_____________________
- _centromeres split, separating chromatid pairs_________________________________
- _chromatids pulled by spindles to opposite poles_______________________________
(4) _telophase_____________________
- _chromosomes stop moving _______________________________________________
- _ nuclear envelope starts to reform _________________________________________
- _chromatin condenses____________________________________________________
- _cell pinches inward forming cleavage furrow__________________________________
2. Cytoplasmic Division: Cytokinesis
a. Division of the _cytoplasm__________________________
b. Begins with formation of a _cleavage furrow_ in plasma membrane that pinches inward
VIII. Cellular Diversity
OBJ: Describe how cells differ in size and shape.
• Average humans has about 100 trillion cells of varying sizes
– Cell size is measured in micrometers (µm)
• 1 micrometer = 1 one-millionth of a meter
• Largest cell in human body is an oocyte with a diameter of 140 µm
– Average hair strands is ~100 µm in diameter
• Cells can be round, oval, flat, cube-shaped, column-shaped, elongated, star-shaped, cylindrical,
or disc-shaped
– Shape is related to function
** An oocyte is a female germ cell or gamete.
5 points possible
8
Figure 3.22, page 69:
1 point ; ¼ point each
1. How is the shape of the cells in Figure 3.22 related to their functions?
Sperm cell: uses flagella for locomotion
Nerve cell: dendrites like telephone wires to transmit messages
Smooth muscle cell: long cylinder to allow it to stretch and contract
Red blood cell: disc-shaped to allow ease of movement through circulatory system without risk
of clogging
IX. Aging and Cells
OBJ: Describe the cellular changes that occur with aging
As we age our cells ability to divide is diminished.
DNA sequences that code for cell division break down.
Free radical control becomes limited.
Autoimmune responses slow down.
Critical thinking applications:
2 points each = 4 points
1. Jethro loves his French fries super-sized with extra salt. He dropped Anatomy & Physiology last
semester but remembers something about a pump. “Hey, I’m a big guy. I need the extra salt to
power my sodium pump.” How well does Jethro remember his Anatomy & Physiology?
Salt is composed of sodium and chloride; sodium-potassium pump transports sodium out of the
cell and potassium into the cell by active transport. ATP powers the pump.
2. Your friend Sam works a highly stressful job as a neurosurgeon. His diet during long, extended
shifts consists mainly of chocolate and Sweet Ice Tea. He has been sick a lot and feels that his
job is prematurely aging him. Your response to Sam is that he should examine his diet. Why do
you respond this way?
Sam has several risk factors that could be contributing to his “premature aging”. High levels of
stress can shorten the protective telomeres on the ends of chromosomes, contributing to aging
and eventual death of cells. Glucose cross-links that form between proteins can contribute to
loss of elasticity, which ages tissues. His immune system may be malfunctioning, producing
autoimmune responses that can also affect the aging process.
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