Cells and Their Organelles
The cell is the basic unit of life. The following is a glossary of
animal cell terms. All cells are surrounded by a cell membrane. The
cell membrane is semipermeable, allowing some substances to pass into
the cell and blocking others. It is composed of a double layer of
phospholipids and embedded proteins. Plant cells have an additional
layer surrounding them called the cell wall. The cell wall is made of
nonliving material called cellulose. The centrosome (also called the
"microtubule organizing center") is a small body located near the
nucleus. The centrosome is where microtubules are made. During cell
division (mitosis), the centrosome divides and the two parts move to
opposite sides of the dividing cell. The centriole is the dense center of
the centrosome. Microtubules are shaped like soda straws and give the
nucleus and cell its shape.
1. At what level of organization does life begin? The cellular level
2. What surrounds all cells? Cell Membrane
3. What is meant by semipermeable? Some Substances can pass
through the cell, while others are blocked
4. What 2 things make up the cell membrane? Phospholipids and
Embedded Proteins
5. The cell membrane is also called the
_P_ _l__ _a__ _s__ _m__ __a_ membrane.
6. What additional layer is found around the outside of plant cells
and bacteria? Cell Wall
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7. Centrioles are found at the center of the
_C_ _e__ __n_ _t__ __r_ __o_ _s__ _o__ _m__ __e__.
8. How do they help the cell? Make microtubules (aid in shape of
Cell) and aid in cell division
The nucleus in the center of a cell is a spherical body containing
the nucleolus which makes ribosomes. The nucleus controls many of
the functions of the cell (by controlling protein synthesis). It also
contains DNA assembled into chromosomes. The nucleus is surrounded
by the nuclear membrane. Materials can move from the nucleus to the
cytoplasm through nuclear pores in the membrane around the nucleus.
Cytoplasm is the jellylike material outside the cell nucleus in which the
organelles are located. All cells, even prokaryotes contain small bodies
called ribosomes. Proteins are made by by the ribosomes in a process
called protein synthesis.
9. Where is DNA found inside a cell? In Nucleus on Chromosomes
10. DNA coils tightly during division and assembles into visible
_C_ __h_ __r_ _o__ _m__ _o__ _s__ __o_ _m__ _e__ _s__.
11. Where are organelles located? Cytoplasm
12. Where are proteins made in a cell? In ribosomes
13. Do all cells need ribosomes? Yes, they are vital to the cell
14. The process of making proteins is called
___protein__________ __synthesis____________________.
Rough endoplasmic reticulum (rough ER) is a vast system of
interconnected, membranous, infolded and convoluted sacks that are
located in the cell's cytoplasm. The ER is continuous with the outer
nuclear membrane. Rough ER is covered with ribosomes that give it a
rough appearance. Rough ER transports materials through the cell and
produces proteins in sacks which are sent to the Golgi body. The Golgi
apparatus or Golgi complex is a flattened, layered, sac-like organelle
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that looks like a stack of pancakes. The Golgi body modifies &
packages proteins and carbohydrates into membrane-bound vesicles
for "export" from the cell. Smooth ER does NOT have ribosomes on
its surface. It makes proteins and lipids that will be exported by the
cell. It also controls the Calcium level in muscles and detoxifies
poisons, alcohol, and drugs.
15.
How does rough ER differ from smooth ER? No
ribosomes_______________
16. Rough ER is connected to the __Nuclear___________ membrane
and to ___smooth_______ER.
17. Proteins made by rough ER travel to the Golgi in sacks. The Golgi
____modifies________ and ___packages________ proteins for
export out of the cell.
18. Give 3 jobs for smooth ER.
a. Makes proteins and lipids
b.
Controls calcium levels
c. Detoxifies poisons, alcohol, and drugs
Chloroplasts are elongated or disc-shaped organelles containing
chlorophyll that trap sunlight for energy. Photosynthesis (in which
energy from sunlight is converted into chemical energy - food) takes
place in the chloroplasts. Only plant cells, not animal cells, can make
their own food. Cells also contain fluid-filled sacs called vacuoles. The
vacuole fills with food being digested and waste material that is on its
way out of the cell. In plant cells, a large central vacuole takes up
most of the space in the cell. Mitochondria are spherical to rodshaped organelles with a double membrane. The mitochondrion
converts the energy stored in glucose into ATP (adenosine
triphosphate) for the cell. Both chloroplasts and mitochondria have
double membranes and their own DNA. Cells also contain spherical
organelles called lysosomes that contain digestive enzymes. Nutrients
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are digested by the cell here, as well as, old cell organelles that are
going to be recycled.
19. What process takes place inside chloroplasts? Food production
20. What is the energy for this process? Sunlight
21. What pigment traps the energy? Chlorophyll
22. Chloroplasts are found in what type of cell(s)? Plant
23. Both chloroplasts and mitochondria are like in that they both
have _____Double____________ membranes and their own
___DNA____.
24. Food, water, and wastes are stored inside
___vacuoles___________.
25. Digestion takes place inside _____lysosomes________
containing ___digestive enzymes__________.
26. The largest organelle in plants is the ____central________
____vacuole_________.
27. What organelle breaks down and recycles worn out cells?
The lysosomes do this
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Figure 1 - Animal Cell
Cell Membrane (orange)
Cytoplasm (white)
Nuclear Membrane (black)
Ribosomes (red)
DNA (pink)
Nucleolus (brown)
Golgi (purple)
Rough ER (dark blue)
Smooth ER (light blue)
Mitochondria (yellow)
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Microtubules (green)
Lysosome (grey)
Vacuole (green blue)
Figure 2 – Plant Cell
Cell Membrane (orange)
Cytoplasm (white)
Nuclear Membrane (black)
Ribosomes (red)
DNA (pink)
Nucleolus (brown)
Golgi (purple)
Rough ER (dark blue)
Smooth ER (light blue)
Mitochondria (yellow)
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Microtubules (green)
Lysosome (grey)
Central Vacuole (green blue)
Cell Wall (green)
Chloroplasts (light green)
Figure 3 – Bacteria Cell
Prokaryotes cells are the simplest of all the cells. Bacteria are prokaryotes and they fall
into two major categories: The Kingdom Eubacteria and the Kingdom
Archaebacteria. Eubacteria are common types that occur all around us, usually they are on
surfaces and in the soil. You can only find Archaebacteria in extreme environments, like
hot sulfur springs. Archaebacteria are thought to be some of the oldest life forms on earth.
Most bacteria don't make their own food. That means they have to rely on other organisms
to provide them with food. These bacteria have to break down, or decompose, other living
things to obtain energy.
Bacteria have a very simple cell design. Most of them have a thick outer covering called
the cell wall Just within the cell wall is the cell membrane. Along the surface of the
bacteria cell, you might encounter structures called pilus, whose job is to help the bacteria
stick to surfaces. Bacteria might also need to move around in their environment, so they can
have structures called flagella, which resemble tails. The watery interior of the cell is
called cytoplasm, and it has the texture of jello. Sprinkled throughout the cell are small
roundish structures called ribosomes. Ribosomes make proteins for the cell. Every
prokaryote cell has DNA floating within the cytoplasm, which usually looks like a twisted
strand of spaghetti called a nucleoid. DNA contains the instructions for the cell, basically it
is the control center.
Cell Membrane (orange)
Cytoplasm (white)
Ribosomes (red)
DNA - nucleoid (pink)
Cell Wall (green)
Pillus (light brown)
Flagella (yellow)
Questions: 1. What are the oldest life forms on earth?
_____________Bacteria___________________
2. What part of the bacteria cell helps it stick to
surfaces?_______Pillus______________________
3. What is the control center of the bacteria cell?____DNA_/
Nucleoid Region____________________
4. What part of the bacteria cell helps it
move?__________Flagella_____________________
5. Where do Archaebacteria live?_____Hot Sulfur
Springs______________
6. To what kingdom do common bacteria belong?
Bacteria______________________________________
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Complete the following table:
Organelle
Cell membrane
Plant/Animal/Both
Both
Barrier/Keeps things in and out
Cell wall
Plant
Cell Shape / Protection
Cytoplasm
Both
Gel substance organelles float in
Centrosome
(centrioles)
Both
Microtubules
Both
Nucleus
Both
Nuclear Membrane
Both
Nucleolus
Both
Ribosome
Both
ER
Both
Golgi
Both
Vesicles
Both
Mitochondria
Both
Function
Makes microtubules / Aids in
Cell Division
Helps with division DNA / Aids in
cell shape
Houses DNA and RNA / Control
Center
Double membrane that lets
things in and out of the Nucleus
Inside the nucleus where
ribosomes are made
Produces proteins and is
composed of RNA
Produces proteins and lipids and
transports them
Packages and Distributes things
for the cell
Membrane bound sacs that
transport substances inside the
cell
Breaks down food to make
energy (ATP)
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Chloroplast
Central
Vacuole/Vacuole
Plant
Takes energy from the sun and
uses it to help make energy for
the cell
Aids in cell shape / regulates
water (large) / digestions
Plant (Central
Vacuole)
Animal (more than
one vacuole)
Lysosomes
Both
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Storage of nutrients and water /
digestion
Breaks down waste for the cell