Chapter 4
Section 3: Looking Inside Cells
Looking Inside Cells
Organelles = tiny structures found inside of the cells.
Think organs of the cell.
The Organelles of the Cell
Cell WallONLY in plant cellsProvides protection and support for the cell.
Think Prison Walls.
The Organelles of the Cell
Cell MembraneControls what enters and exits the cell.
Think prison guard of the cell.
The Organelles of the Nucleus
Nucleus The brain of the
cell, the control center.
Controls all the activities of the cell.
The Organelles of the Nucleus
Nuclear Membrane Protects the
nucleus
Think about the yolk of an egg and how there is a thin barrier that holds it together.
The Organelles of the Nucleus
Chromosomes Rod shaped Contain thin strands
called Chromatin. Chromatin has the
genetic material = DNA
The Organelles of the Nucleus
Nucleolus Produces
ribosomes.
The Organelles of the Cytoplasm
Cytoplasm is the region between the cell membrane and the nucleus.
Cytoplasm is a thick, always moving liquid.
The Organelles of the Cytoplasm
Mitochondria Found in the
cytoplasm Rod shaped
organelles Produce energy The more active the
cell, the more mitochondria they have.
The Organelles of the Cytoplasm
Endoplasmic Reticulum Found in the
cytoplasm Is like a giant maze Carries the proteins
and other materials from one part of the cell to another.
The Organelles of the Cytoplasm
Ribosome Small grain like
bodies attached to the Endoplasmic Reticulum.
Produce proteins Proteins are sent to
the Golgi Bodies
The Organelles of the Cytoplasm
Golgi Bodies Flattened collections of
sacs and tubes. Receive the proteins
and other newly formed material from the endoplasmic reticulum.
Mailroom of the cell. Release materials
outside the cell.
The Organelles of the Cytoplasm
Chloroplasts Capture energy
from the sun.“think solar panels”
Use energy to create food.“photosynthesis”
ONLY in plant cells.
The Organelles of the Cytoplasm
Vacuoles Large water filled sacs Storage area of the
cell. Food Materials Needed Waste products
Without water in the vacuoles, plants begin to wilt.
The Organelles of the Cytoplasm
Lysosomes Small round structures Break down food
particles . Break down old cell
parts so that they can be reused again.
Have powerful chemicals that are contained by a membrane.
Bacterial Cells
Has a cell wall and membrane.Does NOT have a nucleus.Contain ribosomes, but none of the other
organelles found in plant or animal cells.
Prokaryotes vs. Eukaryotes
Organisms that do not contain a nucleus.
PROKARYOTES
Organisms that contain a nucleus.
EUKARYOTES
Structure and Function in Cells
Different cells perform different functions. Examples:
Plants have root cells that are specialized to absorb water from the soil.
Nerve cells are specialized to carry messages that enable the animal to respond to external and internal stimuli. They have long, threadlike projections that act something like telephone wires. These “wires” carry messages throughout your body.
Red blood cells carry oxygen throughout the body. Their thin, flexible structure helps them squeeze through tiny blood vessels.
Levels of Organization
Multi cellular organisms have four levels of organization.
1. Cells
2. Tissues
3. Organs
4. Organ Systems
Smallest
Biggest
Cell
Tissues
A group of similar cells that perform a specific function in an organism.
specialized for functions such as absorbing materials, transporting materials, and support.
Example:Bone tissue produce a hard, strong material
that supports the body.
Tissues
Organs
A structure in the body that is composed of different kinds of tissue.
Example:Bones, which support the body, are hard
and sturdy because of the tissues of which they are composed.
Organs
Organ System
A group of organs that work together to perform a major function in the body.
Example: The skeletal system functions to support the body and
give it shape. The skeleton protects delicate internal organs such as
the brain and lungs. The strength and hardness of bones enable the
skeleton to perform the functions of support and protection.
The structure and arrangement of bones give the body its shape.
Organ System
The 5th Level
Every organism interacts with other organisms and the environment in which it lives.
Scientists add another level of organization: the population.
Population = All the members of one species in a particular area.
