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Complete the following table:
Section 1 Workbook (unit 3) ANSWERS nucleotide
DNA
Name: _______ RN
B1. Analyze the functional inter-relationships of cell structures.
1)
Describe the function and structure of these organelles.
Cell Organelle
cell membrane
Function
Structure
Defines cell boundary, regulates what -phospholipid bilayer with protein, cholesterol, &
goes in & out of cell
carbs
Support & structure to cell – protects
-
cellulose
Photosynthesis
-
grana & stroma, double membrane
Organelle movement, anchor
organelle, support
-
protein fibres
Contains organelles
-
semi fluid medium
Processing, packaging & distribution
of proteins & lipids
-
stack of flattened sacs
Intracellular digestion
-
large membrane bound sacs
Cellular respiration
-
double membrane with cristae & matrix
Stores genetic info., synthesize DNA
& RNA, controls cell activities
-
double membrane, chromatin
nucleus
Allow certain molecules in and out of
nucleus
-
hole in nuclear membrane
nuclear pore
Makes rRNA
-
concentrated area of chromatin, RNA, and
proteins
cell wall
chloroplast
cytoskeleton
cytoplasm
Golgi bodies
lysosomes
mitochondria
incl cristae and matrix
nucleolus
Stores genetic information & controls cell activities
loosely wound DNA around histone proteins
Separates nucleus from cytoplasm
-
double membrane with pores
Tightly wound DNA for cell division
-
tightly wound DNA around histone proteins
Protein synthesis
-
small & large subunits, rRNA & proteins
Make large proteins faster
-
group of ribosomes
SmootER
Makes lipids
-
membranous, no ribosomes
roughER
Makes proteins
-
membranous, has ribosomes
Long- term storage
-
large membrane bound sacs
Short- term storage
-
small membrane bound sacs
chromatin
nuclear envelope
chromosomes
ribosomes
polysomes
vacuoles
vesicles
Page 1 of 14 2)
Label each organelle that is depicted in the chart.
mitochondrion
chloroplast
Golgi body
vesicle
rough ER
smooth ER
Chromosomes
Lysosome
Chloroplast nuclear envelope
nuclear pore
Page 2 of 14 mitochondrion
nucleus
3)
Label the cristae and the matrix:
4)
Cristae
Matrix
Identify and label the parts of the following organelles.
rough ER
Label the vesicles
Rough ER with ribosomes
Golgi body surrounded by vesicles
5) State the balanced chemical equation for cellular respiration and explain the significance of the
mitochondria in this process.
C6H12O6 + 6O2 ⇒ 6CO2 + 6H2O + ATP
- Cellular respiration occurs in the cristae of the mitochondrion
6)
Describe how the following pairs of organelles function to compartmentalize the cell and
move materials through it. Where are proteins made and how are they processed, transported
and exported?
a. Rough and Smooth ER
•
•
•
•
The rough and smooth ER are membranous channel that are continuous with the nuclear
envelope, which separates the contents of these organelles from the cytoplasm.
The rough ER produces proteins due to the ribosomes attached to it.
The smooth ER produces lipids.
The rER follows right after the nucleus and the sER comes right after the rER.
Page 3 of 14 b. Golgi bodies and vesicles and lysosomes
•
•
•
The Golgi modifies, packages, and processes proteins – it is a group of flattened sacs in
the cytoplasm.
Vesicles isolate substances inside their membrane and transports substances from the
ER to the Golgi to the cell membrane for exocytosis.
Lysosomes isolate substances inside for intracellular digestion ex) old organelle or
bacteria – made by the Golgi
Page 4 of 14 7)
Label plasma membrane, mitochondrion, centriole, rough ER, cytoplasm, smooth ER, Golgi
body, microfilaments, microtubules, ribosomes, nucleus, nuclear envelope, nuclear pore,
nucleolus, chromatin, lysosome
Mitochondrion
centriole
Cytoplasm
smooth ER
Golgi body
cent
riole Nucleus
rough ER
nuclear pore
nuclear envelope
Nucleolus
Chromatin
microtubules
Plasma membrane Lysosome
Ribosomes
Microfilaments
Page 5 of 14 Organelles work together: rER makes proteins (or sER makes lipids). Transport vesicle moves it to the Golgi body where
Label and explain the inter-­‐relationships between cell organelles the protein or lipid is modified and packaged. A secretory vesicle takes lipid or protein to cell membrane for exocytosis.
Smooth ER
Rough ER
transport vesicle
transport vesicle
lysosome
Golgi body
endocytosis
secretory vesicle
exocytosis
Page 6 of 14 B9. Analyze the structure and function of the cell membrane
8)
Label the following parts of the cell membrane in the diagram below: hydrophobic
region, hydrophilic region, phospholipid, carbohydrate, glycoprotein, glycolipid, cholesterol.
carbohydrate
glycolipids
glycoprotein
glycoprotein phopholipid
hydrophobic region
hydrophilic region
cholesterol
9)
What are the main functions of proteins in the cell membrane?
To determine the function of the membrane, moves substances across the membrane and transmits signals into cell 10) Explain why the cell membrane is described as “selectively permeable”.
Some substances can freely cross the cell membrane while others cannot. For example, lipid soluble, small, uncharged molecules cross easily while charged, large molecules need help to cross. 11) How does a molecule’s size, shape, charge and lipid solubility affect its permeability?
For example, lipid soluble, small, uncharged molecules cross easily while charged, large molecules need help to cross.
12) What is a concentration gradient?
Where there is a different concentration of a substance on either side of the cell membrane 13) What form of energy is used?
ATP
Page 7 of 14 14) Complete the following table
Comparison of Membrane Transport Processes
T y pe of transport
diffusion
osmosis
facilitated
active
endocytosis
Uses
channel
or carrier
protein?
(Y or N)
Uses
energy?
(Y or N)
With
No
No
Oxygen, carbon dioxide, alcohol,
urea
With
No
No
Water
With
Yes
No
Sugar & amino acids
Against
Yes
Yes
No
Yes
Other sugars, amino acids &
ions
Large macromolecules
Concentration
Gradient (with
or against)
Types and sizes of molecules
transported
phagocytosis
omit
pinocytosis
omit
No
Yes
Small, liquid, solutes
Against
No
Yes
Large molecules
exocytosis
15) What process is being depicted in the diagrams below?
Diagram A:
Endocytosis
= phagocytosis
Diagram B:
Exocytosis
Page 8 of 14 16)
17)
What are the functions of the following membrane proteins?
•
Receptor
Receive signal ex) hormone
•
Enzyme
speed up chemical reactions
•
Glycoprotein
cell recognition
A) Explain how the following factors affect the rate of diffusion across a cell membrane:
Factor
Effect:
↑, ↓, or
no change
Explanation
⇑
Molecules speed up and move faster
⇓
Molecules cannot move through the phospholipid
bilayer easily when they get big
⇑
The greater the concentration difference the
faster diffusion occurs because the greater the
“push” created
⇑
The greater the pressure difference the faster
diffusion occurs because the greater the “push”
created
⇓
Because charged molecules need help to cross
due to the hydrophobic, non-polar interior of the
phospholipid bilayer – need protein
increased temperature
increased size of molecule
larger concentration gradient
larger pressure gradient
charged molecules (ions)
instead of neutral molecules
B) Explain osmosis
•
•
Diffusion of water from high to low concentration of water across a
semipermeable membrane.
Water moves from low solute concentration to high solute concentration
Page 9 of 14 18)
Predict and explain the effects of the following environments on osmosis in animal cells.
Use illustrations in your answer.
a. Hypertonic:
•
causes an animal cell to lose water and shrivel up
b. Isotonic:
•
no effect on an animal cell
c. Hypotonic
•
19)
causes an animal cell to gain water and swell – it may even burst (lyse)
In the following diagrams, circle the side in which water diffuse to–side A or B?
Side A
20)
Side A
Describe what has happened to the RBCs in the diagrams below.
Nothing, it is an isotonic solution.
Swells because in hypotonic solution.
Shrivels because in hypertonic solution.
Page 10 of 14 B10. Explain why cells divide when they reach a particular surface
area-to-volume ratio
21)
Complete the table to compare the SA:Volume ratio of two cube-shaped cells.
length of one side (s)
surface area (6s2)
volume (s3)
surface area : volume ratio
22)
Cell #1
Cell #2
2
4
24
96
8
64
24:8 = 3
96:64 = 1.5
Why is the surface area-to-volume ratio important to cells?
To allow for adequate exchange of nutrients and wastes at the cell membrane of
the cell – in order to sustain that cell
23)
How do cells increase their surface area-to-volume ratio without increasing their volume?
Give three examples.
•
Folding, getting thinner, irregular / convoluted shape
•
Ex) intestinal villi, mitochondria, surface of the brain
B11. Analyze the roles of enzymes in biochemical reactions
24)
Explain the following terms:
a. Metabolism:
•
The sum of all the chemical reactions that occur inside a cell
b. Enzyme:
•
A protein that speeds up chemical reactions. (biological catalyst)
c. Substrate:
•
The reactant of an enzymatic reaction – fits into the active site of enzyme and
is used to create the product
d. Coenzyme:
•
An organic, non-protein molecules that helps an enzyme do its job
e. Activation energy:
The amount of energy needed to cause molecules to react to form a product.
Page 11 of 14 25)
Label the parts U through Z.
U = active site; V = enzyme; W = coenzyme; X = substrate; Y = substrate-enzyme complex; and Z
= product
26)
Use a graph to explain how enzymes lower the activation energy of a biochemical
reaction.
Enzymes reduce the amount of energy needed to cause a reaction to occur.
27)
Use a diagram to explain the induced-fit model of enzymatic action.
The active site slightly changes shape to allow for the best fit of the substrate into the
active site of the enzyme
28)
How is the role of an enzyme different from the role of a coenzyme in a biochemical
reaction?
Enzymes speed up chemical reactions while the coenzymes help enzymes do their
job
Page 12 of 14 29)
What is the relationship between some vitamins and coenzymes?
•
30)
Some vitamins are components of coenzyme. If there is a lack of some vitamins there is a lack of the coenzymes. Apply your knowledge of proteins to explain the effects of each of the following on
enzyme activity. Use graphs to help in your explanation.
pH:
An enzyme has an optimal pH depending upon where it functions in the body. If the pH moves away from the optimal pH, the enzyme denatures and enzyme activity decreases temperature:
The optimal temperature is 37°C. If you increase the temperature you increase enzyme activity to a point. If you move up to 40°C, enzyme denatures but reversible. If over 40°C permanent. Temp. below 37°C, enzyme activity decreases substrate concentration:
Increases enzyme activity until all the active sites of enzymes are full and then the saturation point is reached = maximum rate reached for reaction. enzyme concentration:
Increases enzyme activity as long as substrate available. As substrate converted to the product, enzyme activity decreases. If add more substrate, the enzyme activity will increase again. competitive inhibitors:
These molecules block the active so the substrate cannot bind to the enzyme. Competitive inhibitors are so close in shape to the substrate that they can compete for the active site. Therefore, enzyme activity decreases. non-competitive inhibitors:
(e.g. heavy metals)
These molecules decrease enzyme activity or stops it (feedback inhibition / negative feedback). Non-­‐
competitive inhibitors bind to the enzyme at a place other than the active site. A change in pH, temperature, or the addition of a non-competitve inhibitor all cause
denaturation of the enzyme that leads to it no longer being able to function in the body
Page 13 of 14 31)
What is the source gland for the hormone thyroxin? Describe how thyroxin controls
metabolic rate.
•
•
32)
The thyroid gland produces the hormone thyroxin. Thyroxin increases the metabolic rate of cells and regulates growth and development. What is a metabolic pathway? How are enzymes involved in these pathways?
•
•
A metabolic pathway is a series of linked reaction where the product becomes the reactant of the next enzymatic reaction in the series. For each step of the pathway there is a different enzyme needed
Page 14 of 14