Focus Activity
Using your prior knowledge,
draw and label the animal
cell with organelles,
identifying at least 5
organelles.
DO THIS
NOW!!!
Turn in your Chapter 7
Worksheet Packet and
your Microscope Lab if
you didn’t turn it in on
Friday.
Cellular Life
“Can you hear me now?”
Good.
Ch. 7: Cell structure and function
In the book, chapter 7 is about cells and
cell functions. Why do you think it is
important to learn about cells?
Throughout this chapter try to relate
information from Chapter 2 to the
information that you will be getting today
and tomorrow.
Ch. 7: Section Outline
 7-1: Life is Cellular
 The Discovery of the Cell
 Exploring the Cell
 Prokaryotes and Eukaryotes
 7-2: Eukaryotic Cell Structure
 Organelles
 7-3: Cell Boundaries
 Cell Membrane and Cell Walls
 Diffusion and Osmosis
 7-4: The Diversity of Cellular Life
 Unicellular and Multicellular Organisms
 Levels of Organization
The Discovery of the Cell
 Robert Hook
Use a medieval microscope to look at a piece of
cork.
First person to identify cells
Discovery of the Cell (con’t)
 Anton van Leeuwenhoek
First person to observe
living cells
It was he who discovered
bacteria, free-living and
parasitic microscopic
protists, sperm cells, blood
cells, microscopic
nematodes and rotifers, and
much more.
The Discovery of the Cell (con’t)
Cells: the basic unit of life
The Cell Theory:
All living things are composed of cells
Cells are basic units of structure and function in
living things
New cells come from existing cells
Prokaryotes and Eukaryotes
 Prokaryotes: cells that don’t have a nucleus.
Name means “Before Nut”
Small and simple
Free-floating genetic material
Ex: Bacteria
 Eukaryotes: cells that have a nucleus
Name means “True Nut”
Large and complex
Contain membrane bound structure
 Nucleus: large, membrane enclosed structure
that contains genetic material.
Prokaryote vs Eukaryote
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Nucleus
Eukaryotic Cell
Organelles
7-2 Eukaryotic Cell Structure
Organelles: membrane bound structures
within a cell; “little organs”
2 main parts of a cell:
Nucleus
Cytoplasm: portion of cell outside of nucleus
that contains the organelles suspended in a
liquid called cytosol.
Organelles
 When you are writing your notes, think of
analogues in the body that could represent each
organelle.
 Nucleus
The control center of the cell
Contains almost all of a cell’s DNA
Contains the Nucleolus
 Nuclear Envelope: Membrane that surrounds the
nucleus
 Chromatin: Long, stringy DNA bound to proteins
Organelles (con’t)
 Chromosomes: compact DNA (made when a cell
is about to divide)
What is the difference between chromatin and
chromosomes?
 Nucleolus: Inside the nucleus, it’s function is the
production and maturation of ribosomes.
 Ribosomes
The site for protein synthesis
Made from RNA and proteins
Organelles (con’t)
Endoplasmic Reticulum
Name means “within the cytoplasm little net”
Internal membrane system
Lipids assembled here
Proteins made to leave the cell come here too.
Two types
Rough Endoplasmic Reticulum
Smooth Endoplasmic Reticulum
Organelles (con’t)
Rough Endoplasmic Reticulum
Ribosomes are found on the surface.
They chemically modify proteins
Smooth Endoplasmic Reticulum
No Ribosomes are found on the surface.
Synthesizes lipids, fatty acids, and steroids
Plays an important part in Carbohydrate
metabolism
Enzymes in the Smooth ER detoxify drugs
Organelles (con’t)
Golgi Appartus
The Packaging center
Modifies, sorts, and ships proteins that come
from the ER (sends them where they need to
go)
Lysosomes
Small, filled with enzymes
Do the “digesting” of the cell
Breakdown proteins, lipids, etc., and old
organelles
Organelles (con’t)
Vacuoles
Saclike structures used for storage
Pump out water
Store water (plants-central vacuole)
Mitochondria and Chloroplasts
Source of Energy
Organelles (con’t)
 Mitochondria
Organelles that convert chemical energy stored in food
into ATP
 Enclosed by two membranes
• Outer
• Inner (folded inside)
 Inherited from egg cells
 Chloroplasts
Organelles that capture energy from sunlight and
convert it into chemical energy and sugar
 Found only in plants
 Mitochondria and chloroplasts contain their own
small DNA Molecules (genetic info)
Organelles (con’t)
Cytoskeleton
The support system of a cell
Made of protein filaments that help maintain
shape of a cell (ex. Microtubules and
microfilaments)
The cytoskeleton is also a part of movement for a
cell. Microtubules help build cilia and flagella.
Cytoskeleton
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Mitochondrion
Organelles
Special Organelles
Some organelles are only found in plants and
only found in animals
Chloroplasts (plants)
Centrioles (animals)
Centrioles
Important in cell division
Creates Microfilaments that attach to chromosomes
to separate the replicated DNA.
7-3: Cell Boundaries
This chapter talks about the boundaries of
the cell.
You will also learn about diffusion and the
different types
Active and passive Transport
Facilitated Diffusion
Osmosis
Endocytosis and Exocytosis
7-3: Cell Boundaries
 Cell Membrane
The thin, flexible barrier that surrounds all cells
 Some cells have another layer outside this called a cell
wall.
Function:
 Regulates what enters and leaves cells
 Provides protections
Structure
 Lipid Bilayer: Double layer of phospholipids
• Fluid Mosaic Model
 Carbohydrates attached to outside bilayer
 Proteins found within it
Lipid Bilayer
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
of cell
(cytoplasm)
Protein
channel
Lipid bilayer
Cell Boundaries (con’t)
Cell Walls
Found in plants, fungi, and some prokaryotes
Outside of cell membrane
Functions
SUPPORT! SUPPORT! SUPPORT!
Protection
Made from carbohydrates (cellulose) and
proteins
Animal Cell
The Cell (plant)
Diffusion Through Cell Boundaries
Concentration: The mass of solute in a
given volume of solution ex: 4g/L
Cytoplasm contains different concentration of
different solutes
Particles in a solution are constantly
moving and tend to spread out evenly
Brownian Movement
Diffusion through Cell Boundaries
 Diffusion: the movement of particles from an
area of high concentration to an area of low
concentration
 Equilibrium: When the concentration gradient of
a solute is the same throughout a system
 *Diffusion requires no energy and is called
“Passive Transport”*
 Particles diffuse across cell membranes
Semi-permeable membrane
Osmosis
Osmosis
The diffusion of water across a selectively
permeable membrane (again a type of Passive
Transport)
WATER moves from an area of low particle
concentration to an area of high particle
concentration.
Isotonic
Hypertonic
Hypotonic
Tonicity
Osmosis
Facilitated Diffusion
Facilitated Diffusion
The Process of particles moving down their
concentration gradient (high to low) with the
help of a protein channel
Does not require energy (passive)
Protein channels are specific in which
molecules they aid
Facilitated Diffusion
Glucose
molecules
High
Concentration
Cell
Membrane
Low
Concentration
Protein
channel
Active Transport
Active Transport
The movement of particles against the
concentration gradient-requires energy
Carried out by protein “pumps”
Very Large molecules (too big to cross the
membrane), move by endocytosis and
exocytosis.
Active Transport
Molecule to
be carried
Energy
Molecule
being carried
Active Transport (con’t)
 Endocytosis
The process of taking in material by means of infoldings
or pockets of the cell
 Exocytosis
The membrane of a vacuole, containing water, fuses
with the cell membrane (spilling the contents out)
 Phagocytosis
Cell “eating”
 Pinocytosis
Cell “drinking”
7-4: The Diversity of Cellular Life
Sometimes a single cell IS the whole
organism.
Single-celled organisms are called
unicellular organisms.
Can you name any?
Unicellular Organisms
The Diversity of Life
Organism that are made up of many cells
are called multicellular organism
Cell Specialization
The Process of cell’s becoming specific for a
certain tasks
Red Blood Cells, muscle cells
Cell Specialization occurs in multicellular
organisms.
What are Stem Cells?
Levels of Organization
In multicellular organisms, there are levels
of organization used to describe cells:
Cells the simplest level
Tissues- groups of cells that work together to
perform a particular function
Organs-groups of tissues that work together
Organ Systems – Groups of organs that work
together
Level of Organization
Muscle cell
Smooth muscle tissue
Stomach
Digestive system