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 Wall ONLY in plant cells Provides protection and support for the cell. Think Prison Walls.

The Organelles of the Cell Cell Membrane Controls 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 5 th 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.