Download Cell Structure and Function

Cell Structure and Function
Cells
•  Smallest living unit
•  Most are microscopic
Characteristics of All Cells
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A surrounding membrane
Protoplasm – cell contents in thick fluid
Organelles – structures for cell function
Control center with DNA
Cell Types
•  Prokaryotic
•  Eukaryotic
Prokaryotic Cells
•  First cell type on earth
•  Cell type of Bacteria and Archaea
Prokaryotic Cells
•  No membrane bound nucleus
•  Nucleoid = region of DNA concentration
•  Organelles not bound by membranes
Eukaryotic Cells
•  Nucleus bound by membrane
•  Include fungi, protists, plant,
and animal cells
•  Possess many organelles
Protozoan
Representative Animal Cell
Representative Plant Cell
Organelles
•  Tiny cell structures that are
specialized parts of a cell that
have specific functions – a cell
“organ.”
Plant Cell
Animal Cell
CELL MEMBRANE
•  – “gate keeper”
•  outer boundary (or layer) of
the cell
•  controls the movement of
materials into and out of the
cell
Cell Parts and Functions
Cell Membrane
Protects the cell
Lets things in and
out of the cell
Location: around
the cell
Common features of all cells
1. Cell Membrane – selectively/
differentially permeable (lets
some things in and out)
CELL WALL
•  found in plant cells
•  tough rigid boundary – made
of cellulose
•  gives cells their shape (it also
provides protection, as well
as support)
Cell Wall Differences
•  Plants – mostly cellulose
•  Surrounds plasma membrane
CYTOPLASM
•  – “cell fluid”
•  a gel-like material inside the
cell
•  Many cellular activities occur
here and where the organelles
are contained
Cytoplasm
•  Viscous fluid containing organelles
•  components of cytoplasm
–  Interconnected filaments & fibers
–  Fluid = cytosol
–  Organelles (not nucleus)
–  storage substances
Cell Parts and Functions
Cytoplasm
Gel-like substances, holds
all Organelles in cell
Location: in cell
NUCLEUS
– “brain
of the cell”
•  controls cell processes
•  Contains DNA or chromosomes
- the heredity material or
genetic blueprint of the cell
Nucleus
•  Control center of cell
•  Double membrane
•  Contains
–  Chromosomes
–  Nucleolus
DNA
•  Hereditary material
•  Chromosomes
–  DNA
–  Protiens
–  Form for cell division
•  Chromatin
NUCLEAR MEMBRANE
•  – materials pass in and out
through tiny holes called
porins
Cell Parts and Functions
Nuclear Membrane
Protects nucleus
Lets things in/out of
nucleus (pores)
Location: around
nucleus
cell
NUCLEOLUS
•  – ribosomes are made here
Cell Parts and Functions
Nucleolus (Nucleoli)
Makes ribosomes
Location: inside
the nucleus
(dark spot)
cell
Nucleolus
•  Most cells have 2 or more
•  Directs synthesis of RNA
•  Forms ribosomes
CHLOROPLASTS
•  – “energy
processing organelles”
•  found only in plant cells
•  place where food is made for
plant cells
Chloroplasts
•  Derived form photosynthetic bacteria
•  Solar energy capturing organelle
Cell Structures and Functions
Chloroplast
Traps suns energy
and Makes food
Location: in plant
cells
MITOCHONDRIA
•  – “powerhouse”
•  converts food (glucose) to
energy (ATP)
Cell Parts and Functions
Mitochondria
Makes energy/
powerhouse
Location: in
cytoplasm
Mitochondria
•  Break down fuel molecules (cellular respiration)
–  Glucose
–  Fatty acids
•  Release energy
–  ATP
RIBOSOMES
•  – “protein factories”
•  place where protein is made in
the cells
•  some are attached –
some float in the
cytoplasm
Cell Parts and Functions
Ribosome
Makes proteins
Location:
in cytoplasm
or
Attached to
E.R.
ENDOPLASMIC RETICULUM
•  – “conveyer belt”
•  transports synthesized proteins
throughout the cell
Cell Parts and Functions
Endoplasmic Reticulum (E.R.)
Transports materials and sends messages to all
parts of the cell
Two types: smooth and rough (has ribosomes)
Location: attaches from cell membrane to nuclear
membrane
Rough E.R.
Rough Endoplasmic Reticulum
•  Ribosomes attached to surface
–  Manufacture protiens
–  Not all ribosomes attached to rough ER
•  May modify proteins from ribosomes
Smooth Endoplasmic Reticulum
•  No attached ribosomes
•  Has enzymes that help build molecules
–  Carbohydrates
–  Lipids
GOLGI BODIES (Apparatus)
•  sort, modify, process, and ship
the proteins through the cell
•  (Also known
As GOLGI
Apparatus)
Golgi Apparatus
•  Involved in synthesis of plant cell wall
•  Packaging & shipping station of cell
Cell Parts and Functions
Golgi Bodies/Apparatus
Packages and secretes
(gets rid of) waste
Location: in
cytoplasm
GOLGI APPARATUS
VACUOLES
“storage”
•  store water, sugar, salts,
nutrients, & wastes in cells
•  maintains the proper pressure
to provide structure
and support in
plant cells
•  –
Vacuoles
•  Membrane bound storage sacs
•  More common in plants than animals
•  Contents
–  Water
–  Food
–  wastes
Cell Parts and Functions
Vacuole
Stores food and water
Location: in cytoplasm
Vacuole
LYSOSOMES
•  contain chemicals that break
down waste materials.
Lysosomes
•  Contain digestive enzymes
•  Functions
–  Aid in cell renewal
–  Break down old cell parts
–  Digests invaders
Cell Parts and Functions
Lysosome
Contains digestive enzymes
Destroys bacteria, old cell
parts…
Location: in cytoplasm