HONORS BIOLOGY
CHAPTER 5 REVIEW
#1
• Why is fluid mosaic a good
description of the plasma membrane?
• Structures shift in place
• Watery hydrophilic heads and
hydrophobic (fatty tails)
#1
Why is the cell membrane
called a phospholipid bilayer?
Two layers of phospho heads
and fatty acid tails
#2
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• Six functions of proteins in a
plasma membrane: p.74
Attach to ECM
Signal transduction
Transport
Intercellular junction
Cell-cell recognition
Enzymatic activity
#3
• Can easily enter
• Hydrophobic
molecules (oil
soluble):
• O2, N2 (small)
• Nonpolar: benzene
• Very small uncharged
or small polar
molecules: H2O,
Urea, glycerol, CO2
• Can NOT easily enter
• Large uncharged
Glucose,Sucrose
• Polar molecules
sucrose (see OH
groups)
• Hydrophilic
• Ions (charged) H+ ,
Na+ , HCO3 , K+,
Ca2+, Cl-, Mg2+
#4
• 3 types of passive transport
• Diffusion-just passing of hi to low
• Osmosis-passing of water thru a
selectively permeable memb.
• Facilitated – Hi to low through a
protein channel
#5
• What does it mean to go “down
the gradient?” (passive)
• Move from hi to low concentration
• What does it mean to go “against
the gradient?” (active transport)
• Move from low to high (with
energy-usually ATP)
#6
• What direction does the water flow if a cell
of 4% solutes is placed in:
10%
4%
0%
#6
• What direction does the water flow if a cell
of 4% solutes is placed in:
• REMEMBER: HYPO TO HYPER
10%
4%
4%
0%
#7
• What is tonicity?
• Measure of osmotic pressure
gradient determined by the solute
concentration that cannot cross
the selectively permeable
membrane
#7
• Note water flows from high water
concentration to low (hypo to hyper)
#8 Animal Cells p.77
#8 Plants
#9
How does the contractile vacuole
control water in a paramecium?
Contractile vacuole youtube
Water squeezed out of vacuole
#10 p. 78
• What is an aquaporin?
• Integral membrane proteins
moving water
• 3 billion more times than
just moving through a
regular plasma membrane
#11
• Exocytosis and endocytosis are both
active transport.
Protein channels span the membrane.
Endocytosis and exocytosis engulf the
particle with the membrane.
#12
– Large
Particle
liquid
drops
receptors
specific
#13
• Ability to cause change or do
work
• L. energy
• Thermal energy
• O. heat
13
• Energy as a result of location or structure
• I. potential
• Type of energy released or need in
molecules
• N. chemical
#13
• Study of energy transformations
• M thermodynamics
• Reaction that releases energy
• E. exergonic
#13
• Makes products rich in
potential energy
• G. Endergonic
• Energy of motion
• J. kinetic
#13
• Measure of disorder
• B. Entropy
• Energy in the universe is constant
• C.1st Law of Thermodynamics
#13
• Energy from exergonic to run
endergonic
• K. Energy coupling
• Total of an organism’s chemical
reactions
• F. metabolism
#13
• Series of chemical reactions.
• A. Metabolic pathway
#13
• Energy conversions increase the entropy
• D. 2nd Law of Thermodynamics
• Cells use oxygen to release energy from
molecules
• H. Cellular respiration
#14
• What does ATP stand for?
• Adenosine triphosphate
#15
• What part of the ATP
molecule is lost or
gained?
• Last Phosphate
• Is ATP recyclable?
• YES
#16
• Is ATP made by
phosphorylation?
• YES ADP + P = ATP
ADP is made by hydrolysis.
ATP = ADP + P
#17
• Is ATP made from exergonic
reactions or endergonic?
• Endergonic
#18
• What is activation energy?
• Amount of energy needed to get a
reaction going.
• Why is this energy needed?
• Reactants are stable and bonds
need to be broken or distorted.
#18
• How do enzymes affect the amount of
activation energy needed?
• Reduces the activation energy needed
• Why?
• Enzyme brings the reactants together.
#19
• Why are enzymes called “Biological
catalysts?
• They are proteins (biological) and speed
up reactions without changing themselves
(catalyst).
#20
• SKETCH HOW AN
ENZYME WORKS:
• Enzyme will bring
substrate(s) together
and contort bonds at
the active site
products
#21
• What is the purpose of the “induced fit”
(hand shake) of an enzyme-substrate
complex?
• The enzyme slightly changes the shape
of the active site to contort/break
substrate bonds.
#22
• Why might too high temperatures make an
enzyme not function properly?
• Denature (unravel) the enzyme and
change the shape of the active site.
#23
• What is the optimal
temperature for
most human
enzymes?
• 35-40o C
• (body temp is
37oC)
• What is the optimal
pH for most
enzymes?
• 6-8
#24
• What is the difference between cofactors and
coenzymes?
• Cofactors are inorganic and coenzymes
are organic.
#25
• Sketch an enzyme with a competitive
inhibitor.
#26
• Sketch an enzyme and its substrate with a
noncompetitive inhibitor.
#27
• What is an allosteric site?
• A site a substrate binds to other than the
active site (an alters the shape of the
protein’s active site)
enzyme
Allosteric site
#28
• Feedback inhibition
• What is it
(negative
called if a cell
feedback)
produces more
product than it
needs and the
product act as
an inhibitor?
#29 MATCH
• Inhibits
prostanglandins
(sensation of pain)
• Blocks bact. Cell
walls
• Blood pressure meds
• Target HIV
Ibuprofen
Penicillin
Beta blockers
Protease
inhibitors
#30
#31
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LABEL THE PLASMA MEMBRANE:
Phospho head
A1
Cholesterol
E
Lipid tail
A2
Protein pump
G
Carbohydrate chain D
Glycolipid
F
#31
• Peripheral protein
• Glycoprotein
• Phospholipid
• Receptor protein
• Passive transport
protein
• H
• I
• A
• B
• C
32.
• If given the
concentrations in
and out of dialysis
tubing of sucrose
solutions predict
movement of
distilled water.
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1M
0.8 M
0.6 M
0.4 M
0.2 M
0.0 M
32.
movement of water
• If given the
concentrations in
and out of dialysis
tubing of sucrose
solutions predict
movement of
distilled water.
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•
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•
1M
0.8 M
0.6 M
0.4 M
0.2 M
0.0 M
in tube
in tube
in tube
in tube
in tube
in/out
What is the molarity of the
potato core? (where line
crosses zero line) 0.3M