Download BIOLOGY Unit 3_Cell Structure and Function_CLASS NOTES

Unit 3: Cell
Structure &
Function
Mrs. Howland
Biology Level 10
Rev. Oct 2015
All living things are made
up of …
 What is the smallest part
of a LIVING thing?
Cell Theory
 All living things are made up of CELLS
 CELLS are the basic units of structure
and function in living things.
 New cells are produced from existing cells
The DISCOVERY of cells
 In the 1600s, scientists began using
microscopes
 Robert Hook looked at cork (plant
material), discovering small ‘chambers’ he
called CELLS (named after the tiny rooms
they resembled!!)
Discovery of BACTERIA
 Anton van Leeuwenhoek looked at pond
water and a sample taken from a human mouth
 This was his drawing of the organisms he saw
in the mouth—these are the organisms we call
BACTERIA!
Check out his
microscope!
CELL TYPES & SIZES
CELL TYPES & SIZES
Prokaryotes vs.
Eukaryotes
We categorize cells into TWO basic types
Prokaryotes
 Do NOT enclose DNA in nuclei
 SMALLER, and SIMPLER structure
 Still grow, respond to environment,
can move, have genetic material in
form of DNA
 BACTERIA!
Eukaryotes
 LARGER and MORE COMPLEX structures
 Highly SPECIALIZED
 CONTAIN internal structures and
organelles
 Plant cells, animal cells, fungi, protists
Cell is like a FACTORY or
CITY
Each part has its own function.
Together, the parts work to
maintain life.
The “JOB” of a cell
 What jobs do cells have to do for an organism to live…
 “Breathe” ~ gas exchange: O2 in vs. CO2 out
 Eat ~ take in & digest food
 Make energy ~ ATP
 Build molecules ~ proteins, carbohydrates, fats,
nucleic acids
 Remove wastes ~ byproducts of chemical reactions,
dead bacteria/viruses/cells
 Control internal conditions ~ homeostasis!!!
 Respond to external environment
 Build more cells ~ growth, repair, reproduction &
development
Organelles
 Organelles are
structures inside cells
 They do the “WORK” of
cells
 Are specialized by
function
Cell Parts and Functions
Cell Parts and Functions
Cell Membrane
 Protects and supports the cell
 Semi-permeable ~ Lets things
in and out of the cell
 Location: around the cell
Cell Parts and Functions
Nucleus
 “Control center” ~
contains DNA
 Location: inside the cell,
near the center
Chromatin
 Strands of information ~
‘instructions’ for the cell
 Location: inside the
nucleus
Cell Parts and Functions
Nucleolus (Nucleoli)
 Makes ribosomes
 Location: inside the nucleus
(dark spot)
Nuclear Membrane
 Protects nucleus
 Lets things in/out of nucleus (pores)
 Location: around nucleus
cell
Cell Parts and Functions
Mitochondria
 Uses food to make chemical
energy in the form of ATP
 “powerhouse”
 Location: in cytoplasm
Golgi Bodies/Apparatus
 Modifies, sorts, packages
proteins and lipids for
transport out of the cell
 (Location: in cytoplasm
Cell Parts and Functions
Endoplasmic Reticulum (E.R.)
 Assembles proteins and lipids
 Two types: SMOOTH and ROUGH (has
ribosomes)
 Location: attaches from cell membrane to nuclear
membrane
Rough E.R.
Cell Parts and Functions
Ribosome
 Synthesizes proteins
 Location: in cytoplasm or
 Attached to E.R.
Cell Parts and Functions
Vesicle
 Membrane-bound sac
 Holds/transports
materials
Vacuole
 Stores food and water
 Location: in
cytoplasm
Cell Parts and Functions
Lysosome
 Use chemicals ~ ENZYMES ~ to LYSE
(break apart) food molecules and old
cells
Cell Parts and Functions
Cytoplasm
 Gel-like substances, holds
all organelles in cell
 Location: in cell
Cytoskeleton
 Maintains cell shape, moves
cell parts, helps cells move
 Actin, tubulin
 Prokaryotes have protein
filaments
 Location: in cell
Cell Parts and Functions
Cilia
 Short hair-like projections
 Used for movement
 Location: outside of cell
Flagella
 Long whip-like tail
 Used for movement
 Location: outside of cell
Cell Structures and
Functions
Chloroplast
 Traps sun’s energy and
makes food
 Location: in plant cells
Cell Parts and Functions
Cell Wall
 Protects and supports plant
 Cells
 Prevents water loss
 Cellulose
 Location: outer layer of plant
cells
Cells and Microscopy
Cells and Microscopy ~
Plant Cells
Onion Cells at 100x
Onion Cells at 400x
Cells and Microscopy ~
ANIMAL CELL
Cheek Cells at 400x
Cells and Microscopy ~
ANIMAL CELL
Muscle Cells at 100x
CELL TRANSPORT
Movement of molecules into and out
of the cell
PASSIVE TRANSPORTDiffusion
 Does NOT require energy
 Molecules move from HIGHER
concentration to LOWER concentration
PASSIVE TRANSPORTOsmosis
 Facilitated diffusion – requires protein
channels
 Water moves across membrane until
dynamic equilibrium is reached
Different Concentrations
inside and outside cells…
 HYPERTONIC ~ Solution outside of cell has
GREATER concentration of particles. Water
moves OUT of cell.
 ISOTONIC ~ Solution outside of cell and
inside of cell have equal concentrations.
Water moves equally in both directions.
 HYPOTONIC ~ Solution outside of cell has
LOWER concentration of particles. Water
move INTO cell.
Effects of Osmosis on
Animal Cells
ACTIVE TRANSPORTRequires energy!!
 Protein pumps – ATP energy pumps
small molecules
 Exocytosis – Sending material OUT of
the cell (BULK TRANSPORT)
 Endocytosis – Taking material INTO the
cell (BULK TRANSPORT)
ACTIVE TRANSPORTRequires ENERGY!!!