7-1: life is cellular 7-2: cell structures 7-3: movement through the membrane 7-4: the diversity of...
TRANSCRIPT
Chapter 7: Cell Structure and
Function7-1: Life is cellular7-2: Cell structures
7-3: Movement through the membrane
7-4: The diversity of cellular life
7-1 Life is cellular
7-1 Life is cellular
7-1 Life is cellularThe Cell Theory
All living things are made up of cells. All cells come from pre-existing cells. Cells are the basic unit and structure of
all living things.Contributors to the Cell Theory
Hooke – Named cells and observed cork Leewenhoek – Observed living cells Schliden – cell theory plants Schwann – cell theory animals Virchow – cell theory reproduction
A : Bacteria Cell
B : Plant Cell
C : Animal Cell
7-1 Life is cellularBasic Cell Structures:
Cell membrane – the thin barrier around all cells
Cytoplasm – the material inside the cell membrane
Ribosomes – small structures that manufacture proteins
7-1 Life is Cellular
Prokaryotes (bacteria)
Small Simple Contain DNA but no
nucleus Examples include:
Escherichia coli Staphylococcus aureus
Eukaroytes Large (in comparison) Complex with many
organelles – specialized structures that perform important cellular functions.
Contain a nucleus that contains DNA
Examples include: Plants Animals Fungi
Biologists divide cells into two basic categories: Eukaryotic cells or Prokaryotic Cells
Cells are Divided Into Two Categories
Prokaryotic Cell
Cell membrane
Cell membrane
Cytoplasm
Cytoplasm
Nucleus
Organelles
Eukaryotic Cell
Prokaryotic Cell
Eukaryotic Cell
Slides of Prokaryotes (Bacteria)
Prokaryote vs. Eukaryote (basic structures)
Cell membraneRibosomesCell wallDNACytoplasm
NucleusMany organellesBigPlantAnimal
DNASmallBacteria
Prokaryotic
Eukaryotic
Which group of cells would be considered prokaryotic?
A
B
C
7-2 Cell StructuresCytoplasm
Structure (What it’s made of):
Thick, jelly-like fluidFunction (What it does):
Holds all organelles Location of many cellular
chemical reactions
7-2 Cell StructuresNucleus
Structure: Nuclear envelope that
contains pores or holes Dark center called a nucleolus which manufactures ribosomes and contains RNA
Packaged DNA called Chromatin
Function: Controls all the cell’s activities Protects the cell’s information Brain of the cell
7-2 Cell StructuresCytoskeleton
Structure: Microtubules –
hollow tubes of protein
Microfilaments – thin narrow fibers
Function: Maintains cell’s
shape Highway system
for organelles
7-2 Cell StructuresCentrioles
Structure: Part of
cytoskeleton Only in animal cells Packs of
microtubulesFunction:
Helps cells to divide
7-2 Cell StructuresCilia/Flagella
Structure: Part of cytoskeleton Microtubules
Function: Movement
7-2 Cell StructuresRibosomes
Structure: Tiny No outer
membrane Found in both
eukaryotic and prokaryotic cells
Function: Make proteins!!!
Draw
7-2 Cell StructuresEndoplasmic Reticulum
Structure: Network of membrane
tubes Rough E.R. is covered
with ribosomes Smooth E.R. has no
ribosomesFunction:
Transports materials within the cell
Modify proteins Filters out toxins
7-2 Cell StructuresGolgi Apparatus
Structure: Stacks of
membranes Looks like
pancakesFunction:
Modify and package cellular materials
“Post office”
7-2 Cell StructuresLysosome
Structure: Membrane filled
with digestive enzymes
Only found in animal cells
Function: Trash compactor/
Stomach of cell Helps fight
infection
VacuolesStructure:
Membrane bagFunction:
Stores food, water and waste
Help give plant cells rigidity
7-2 Cell StructuresMitochondria
Structure: Peanut shaped Folded layers of
membrane inside called, cristae
Function: Powerhouse Cell Respiration
(makes energy)
7-2 Cell StructuresChloroplast
Structure: Green Contains stacks of
membranes Only in plants
Function: Photosynthesis A type of plastid (a
vacuole that contains pigment)
7-2 Cell StructuresCell Membrane
Structure: Phospholipid (fats) bilayer
Proteins Carbohydrates
Function: Creates a boundary
around the cell Regulates what goes
in and out of the cell
CARBS
PROTEIN
LIPIDS
7-2 Cell StructuresCell Wall
Structure:Only in plant cells and bacteria cells
Contains cellulose
Function:RigidityProtection
Organelle Structure Function
Nucleus DNA (chromatin) Nucleolus
Brain
Cell Membrane Phospholipid bilayer Regulates what goes in and out
Cell Wall Cellulose Protection/rigidity
Cytoplasm Jellylike Holds organelles cellular reactions
Cytoskeleton Microtubulesmicrofilaments
Supports the cell moves organelles
Ribosomes Tiny round structuresFound in ER and cytoplasm
Make proteins
ER Network of tubesRough or smooth
Transports proteins gets rid of toxins
Organelle Structure FunctionGolgi Apparatus
Stacks of membranes (pancakes)
Modify and package proteins and other cellular materials (post office)
Vacuoles Saclike structures Stores food, water, and waste
Mitochondria Peanut shapedFolded layers inside (Cristae)
Powerhouse (mighty!)
Chloroplast Only in plantsGreen bundles
Holds pigments and carries out photosynthesis
Lysosome Sac of digestive enzymes
Disposes of wastes (trashcan)
Centrioles Only in animal cells Helps cells divide
Cillia/Flagella Only in animal cellsHairlike projections
Movement of the cell
Centrioles
Nucleolus
Nucleus
Nuclearenvelope
Rough endoplasmic reticulum
Golgi apparatus
Smooth endoplasmicreticulum
Mitochondrian
CellMembrane
Ribosome(free)
Ribosome(attached)
Figure 7-5 Animal Cell
Nuclearenvelope
Ribosome(attached)
Ribosome(free)
Smooth endoplasmicreticulum
Nucleus
Rough endoplasmic reticulum
Nucleolus
Golgi apparatus
Mitochondrian
Cell wall
CellMembrane
Chloroplast
Vacuole
Figure 7-5 Plant Cell
Animal Cells Plant CellsLysosomesCentriolesSmall Vacuole
Cell membraneRibosomesNucleusEndoplasmic reticulumGolgi apparatusMitochondriaCytoskeleton
ChloroplastsCell WallLarge Vacuole
Animal Cells vs. Plant Cells
Identify the plant cells from the animal cells…
A
B
C
Match the Image to the Cell Type
PLANT
ANIMAL
7-3 Movement Through The MembraneParts of a Cell Membrane
Lipid bilayer: phospholipids
Hydrophilic head Hydrophobic tail
Proteins: On top/bottom Through Act as
passagewayCarbohydrates:
Cell Recognition
CARBSPROTEIN
LIPIDS
7-3 Movement Through The MembraneFluid Mosaic Model
Fluid mosaic model: the cell membrane is like a liquid
Phospholipids are constantly changing positions
Membrane is a mix/ mosaic of different chemicalsMembrane is selectively permeable - some things move through and some things do not
7-3 Movement Through The Membrane
Passive transport (high to low)
No energy needed.
Active transport (low to high)
Needs energy.
Diffusion is a type of Passive transportMolecules move down a concentration gradient (High to Low)Diffuse to reach equilibrium: concentration of molecules is the same throughout the space
Equili
brium
7-3 Movement Through The MembraneDiffusion
Boy am I confused!!!
Osmosis is a type of passive transport
Osmosis is the movement of water from a high concentration to a low concentration
Recall:Solute is the
substance being dissolved
Solvent is the substance doing the dissolving
7-3 Movement Through The MembraneOsmosis
Types of Osmotic SolutionsISOTONIC Solution:
Amount of water in and out of cell is equal Result: Even flow of water into and out of cell.
EX: Blood
HYPOTONIC Solution: More water outside than inside the cell. Result: Water rushes in and cell bursts
(cytolysis) or becomes firm (turgor pressure)
HYPERTONIC Solution: Less water outside than inside the cell. Result: Cell shrinks (plasmolysis)
Flash Movie
Animal Cells Only
Plant Cells Only
Plant Cells Only
7-3 Movement Through The Membrane
ISOTONIC
HYPOTONIC HYPERTONIC
Hypotonic Isotonic Hypertonic
Upper Left: ISOTONIC
Upper Right: HYPERTONIC
Lower Left: HYPOTONIC
How do you catch a unique rabbit?
Unique up on it!!!
Which direction are the molecules moving?
What is the net movement of molecules?
What direction will the molecules be moving at equilibrium?
What is the net movement of molecules at equilibrium?
Water 98%
NaCl 2 %
NaCl 6%Water 94%
Animal cells bursting of cells from a hypotonic environment = cytolysis (hypotonic)
Some cells can adapt to hypotonic environments with an organelle called a contractile vacuole – it fills with water and then squeezes it out of the cell.
Plant cells The rigid cell wall prevents bursting Turgor pressure is pressure that water
exerts against the cell wall (hypotonic) Plants without water wilt and die this is called plasmolysis (hypertonic)
7-3 Movement Through The MembraneOsmotic Pressure
Contractile Vacuole
Facilitated diffusion is a type of passive transportFacilitated diffusion is the movement of large molecules across a membraneCarrier proteins – facilitate (help) movement
Ex. Glucose moves through a carrier protein
7-3 Movement Through The MembraneFacilitated Diffusion
7-3 Movement Through The MembraneDiffusion vs. Facilitated Diffusion
Diffusion – High to low
Facilitated Diffusion – High to low with the help of a protein carrier
**
** *** *
*
*
*
*
* *
7-3 Movement Through The MembraneActive TransportMolecule to
be carriedLowConcentration
CellMembrane
HighConcentration
Moleculebeing carried
LowConcentration
CellMembrane
HighConcentration
Energy Energy
Review Movie
Active Transport movement of molecules from low to high concentration
Energy is needed to do this!
Types: Vesicle Transport: Endocytosis – cell
eating/drinking Exocytosis – cell
spitting material out Protein Pumps – use
energy (ATP) to pump materials from low to high concentrations
7-3 Movement Through The Membrane Endocytosis and Exocytosis
Endocytosis Formation of a vesiclePinocytosis: cell drinkingPhagocytosis: cell eatingPhagocytes: eat and kill bacteria in our
bodyExocytosisVesicles fuse with the cell membrane to
release contents into external environment
7-4 The Diversity of Cellular Life
Cells in multicellular organisms are specialized, this mean each cell type has a specific job to keep the whole organism running.
For example: blood cells carry oxygen to all the cells of the body. Nerve cells have the ability to send electrical impulses
throughout the organism.The levels of organization in a multicellular organism are:
Individual cells (heart cell) Tissues (cardiac tissue) Organs (heart) Organ Systems (cardiovascular system)
Objectives Chapter 7Describe the structure of a membrane.Define the fluid mosaic model.Differentiate between passive and active transport.List and define the types of passive transport.Explain the effects of osmosis in different solutions (ex. iso, hypo, hyper.)Identify cells in isotonic, hypertonic, and hypotonic solutions.Explain how some cells/organisms respond to different osmotic environments.List and define the types of active transport.