Download Cell Info and Questions - Manasquan Public Schools

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Cells
Cytology - the study of cells
Cells vary greatly in SIZE and STRUCTURE
Cells have two main parts - NUCLEUS & CYTOPLASM,
Enclosed in a CELL MEMBRANE (also called PLASMA MEMBRANE), which is
extremely thin, often has folds and pouches, and allows certain substances to pass
through it.
Selectively Permeable = controls what enters and leaves the cell, it allows some things
to pass but not others, this is the MAIN FUNCTION of the cell membrane
CYTOPLASM - the area between the plasma membrane and nucleus. Where most
metabolic reactions/activities take place. Filled with a clear fluid called CYTOSOL.
Contains many structures called ORGANELLES
ORGANELLES
1. ENDOPLASMIC RETICULUM (E.R.) - complex system or network of interconnected
membranes, canals, or channels. Connected to cell membrane, nuclear membrane, and
organelles
Function = TRANSPORT SYSTEM
A. Rough ER - where ribosomes are located. Ribosomes manufacture (synthesize)
proteins
B. Smooth ER - no ribosomes, where lipid synthesis takes place
2. GOLGI APPARATUS (BODIES) - series of flattened, membranous sacs near the
nucleus
Function = "Refining", "Packaging", Delivery of proteins
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3. MITOCHONDRIA (-ion = sing.) - Usually numerous, double layer membrane - inner
layer folded to form CRISTAE.
Function = where chemical energy (food substances) is transformed into a useable form
- molecules of ATP (adenosine triphosphate) that are like "packets" of energy. The
process of releasing/transforming the energy from food involves OXYGEN and is called
CELLULAR RESPIRATION
4. LYSOSOMES - quite variable in size and shape. Contain powerful digesting enzymes
- breakdown and destroy foreign particles, microorganisms, damaged or worn out cells
and cell parts
5. CENTROSOME (central body) - Usually near the G.A. and nucleus. Composed of 2
"cylinders" called CENTRIOLES (each composed of numerous microtubules), which
always lie perpendicular to each other. Active involved in cell reproduction - SPINDLE
forms from the centrioles
6. VESICLES - tiny sacs in which substances are transported
7. MICROFILAMENTS & MICROTUBULES - threadlike structures
MICROFILAMENTS - involved in cellular movement, as in muscle cells
MICROTUBULES - larger than filaments, maintain shape ("skeleton" of the cell)
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The NUCLEUS - directs the activities of a cell. Contains GENETIC materials.
Surrounded by a selectively permeable membrane called the NUCLEAR MEMBRANE
or ENVELOPE. Filled with fluid called NUCLEOPLASM
1. NUCLEOLUS - small, dense structures within nucleus, made of proteins and RNA.
No membrane
FUNCTION = produces ribosomes
2. CHROMATIN - loosely coiled "fibers" in nucleoplasm. Forms CHROMOSOMES
during cell reproduction. Composed mainly of DNA (deoxyribonucleic acid) and
PROTEIN. Contains coded information that directs protein synthesis in the cell
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Movement of Substances Through the Cell Membrane
DIFFUSION - molecules move spontaneously (no cellular energy used) from an area of
higher concentration to an area of lower concentration
FACILITATED DIFFUSION - molecules diffuse through a membrane by means of a
carrier molecule transports (requires no energy = PASSIVE TRANSPORT)
OSMOSIS - the diffusion of water through a selectively permeable membrane.
OSMOTIC PRESSURE = pressure to stop osmosis
SOLUTION
Solute = Substance dissolved
Solvent = Substance in which a solute is dissolved (usually water)
Hypertonic Solution = conc. of solute particles is greater outside the cell
Hypotonic Solution = conc. of solute particles is lower outside the cell
Isotonic Solution = conc of solute particles is the same inside and outside the cell
FILTRATION - molecules are forced through a membrane by hydrostatic pressure
ACTIVE TRANSPORT - molecules are moved against the concentration gradient. This
requires the use of cellular energy, also usually involves a carrier molecule.
Exocytosis = transport of particles out of the cell
Endocytosis = transport of particles into th cell
Pinocytosis - liquids taken in, cell engulfs a droplet of water
Phagocytosis -solids taken in. a vesicle forms.
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The Life Cycle of a Cell
A. Mitosis (nuclear division)
B. Cytoplasmic Division (cytokinesis)
C. Interphase (growth)
D. Differentiation - cells become specialized, developing characteristics in structure and
function
MITOSIS
A. PROPHASE
1.
2.
3.
4.
5.
B. METAPHASE
1.
C. ANAPHASE
1.
D. TELOPHASE
1.
2.
3.
4.
5.
E. CYTOKINESIS
INTERPHASE - growth of cell occurs, chromosomes are duplicated and other structures
and organelles are produced
DIFFERENTIATION - occurs as cells multiply and organism develops and grows
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Name:___________________________________________
Cells
1. Cell:
A cell consists of three main parts---the ______________, the cell "stuff" called ______________,
and the outer _________________________.
2. Cell Membrane: The cell membrane is extremely _________and is __________________
permeable.
function: The cell membrane regulates the_________________________________________,
participates in signal transduction, and helps cells adhere to other cells
structure: The basic framework of the cell membrane consists of a double layer of
_________________
_________________ are found in the cell membrane, including some which are transmembrane and
some that are peripheral membrane.
3. Cytoplasm: The cytoplasm consists of a clear liquid called ______________________, a
supportive ____________________, and networks of membranes and organelles.
4. endoplasmic reticulum: provides a tubular __________________________ system inside the
cell.
rough: why does it appear rough? ________________________
What does it function in the synthesis and transport of? _____________________
smooth: Why does it appear smooth? _____________________
What does it function in the transport of? _____________________
5. ribosome: Where are they found? _____________________
What are they composed of? _____________________
What do they help in the production of? _____________________
6. golgi apparatus: is composed of flattened __________and it packages the cells products.
These packages are released in the form of ________________________
7. lysosomes: contain __________________ enzymes to break up old cell components and
bacteria.
They are sometimes called the "______________________________" of the cell.
8. microfilaments and microtubules: are thin threadlike structures that serve as the
_________________________________of the cell.
Microfilaments, made of the protein ____________________, cause various cellular movements.
Mictotubules, made of the globular protein _________________.
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9. centrosome: is a structure made up of two hollow cylinders called ________________________.
What is their function?
10. cilia & flagella: are motile extensions from the cell. Which one is shorter? ______________
What is its function in the human body? _____________________
What is the only flagellated cell in the body? _____________________
11. Nucleus: is bounded by a ___________-layered nuclear membrane containing relatively large
nuclear ______________________ that allow the passage of certain substances.
12. nucleolus: Where is it found? _____________________
Does it have its own membrane? _____________________
What chemicals is it made of? _____________________
13. chromatin: What chemicals is the chromatin made of? _____________________
14. Movement Through Cell Membrane:
The cell membrane controls what passes through it.
PASSIVE TRANSPORT: Mechanisms of movement across the membrane may be passive, requiring
no ______________ from the cell (diffusion, facilitated diffusion, osmosis, and filtration).
diffusion: from area of ___________ concentration to area of low concentration to reach
_____________________________.
osmosis: Only substance that is moved by osmosis is ___________________________.
What substances diffuse in the human body? _____________________
15. Facilitated Diffusion: - uses membrane proteins that function as ______________________ to
move molecules (such as glucose) across the cell membrane.
16. Filtration: Filtration forces molecules through _______________________ and is commonly used
to separate solids from __________________________
17. Active Transport: moves from area of ____________ concentration to area of ____________
concentration. Requires ___________________ proteins: (pumps). Also requires energy in the form
of _______________.
18. Endocytosis and Exocytosis: In _______________________ molecules that are too large to be
transported by other means are engulfed by an invagination of the cell membrane and carried into the
cell surrounded by a vesicle.
_______________________ is a form in which cells engulf liquids.
_______________________ is a form is which the cell takes in larger particles, such as a white blood
cell engulfing a bacterium.
In ___________________________molecules are pushed out of the cell
19. Cell Cycle: The series of changes a cell undergoes from the time it is formed until it
_________________________ is called the cell cycle.
The cell cycle consists of what four stages? ______________________________________
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The cell cycle is highly regulated. Most cells do not divide continually. Cells have a maximum
number of times they can divide because of built-in "clocks"called _____________ on the tips of
chromosomes.
20. Cell Reproduction: There are two types of cell division, mitosis and meiosis. Meiosis produces
______________ cells.
21. mitosis: How many daughter cells are produced in mitosis? ______ Are they identical to the
"mother" cell? _____________
22. interphase: Interphase is a period of great metabolic activity in which the cell grows and 23.
synthesizes new molecules and organelles. During the S phase of interphase, the __________ of the
cell is replicated in preparation for cell division.
24. prophase: What disappears during this phase? _____________________
What appears or becomes visible during this phase? _____________________
25. metaphase: Why is this phase the easiest to see on a microscope slide? (hint, what are the
chromosomes doing?) _____________________
26. anaphase: What characterizes this phase? _____________________
27. telophase: What reappears during this phase? _____________________ What have the
chromosomes done? _____________________
28. Cytokinesis begins during anaphase of mitosis and continues as the cell pinches into
_________________________________
29. differentiation: The process by which cells develop into different types of cells with specialized
___________________ is called differentiation. What controls this?
30. What is the death of a cell called? ______________________
Labeling Practice
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Name:___________________________________Date:______________
Cell Cycle Labeling
11. What moves the chromatids during mitosis? ___________________________________
12. What anchors the spindle? ________________________________________
13. What are the four phases of mitosis? ___________________________________________________
14. How many daughter cells are created from mitosis and cytokinesis? ___________________________
15. During what phase does cytokinesis begin? ________________________________________
16. If a human cell has 46 chromosomes, how many chromosomes will be in each daughter cell? _________
17. If a dog cell has 72 chromosomes, how many daughter cells will be created during a single cell cycle?
______
.....Each of these daughter cells will have how many chromosomes? ____________
18. The nuclear membrane dissolves during what phase? ________________________
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19. In the cell pictured above, how many chromosomes are present during prophase? ________________
20. What structure holds the individual chromatids together? ______________________________
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