Structure and Function of Cells State Objective 3.b.

What are Cells? The cell theory states the following: All living things are composed of cells. Cells are the basic units of structure and function in living things. All cells are produced from other cells.

Two Types of Cells Prokaryotic cells lack membrane-bound internal structures. Ex. Bacteria Eukaryotic cells contain membrane-bound structures Ex. Blood cells (plant and animal cells)

Tour of Eukaryotic Cells

Cell Wall Rigid layer that surrounds the cells of plants and some other organisms(bacteria) It helps protect and support. Made of strong material called cellulose. 5

Cell Membrane The cell membrane protects the contents of the cell and helps control the materials that enter and leave. Allows food and oxygen into the cell and waste products out of the cell. 6

Moving Material into & out of Cells Cell membranes are selectively permeable. Two types: Passive Transport allows materials to pass through the cell membrane without using energy Active Transport requires the cell to use energy by using transport proteins to move materials across the cell membrane

Cytoplasm A thick, clear, gel-like fluid that fills the regions between the cell membrane and the organelles of Eukaryotic cells. Organelles are tiny cell structures that carry out specific functions with-in the cell. 8

Nucleus The nucleus is the cell’s control center, directing all of the cell’s activities. Contains DNA Nucleolus makes ribosomes which are small grain-shaped organelles that make proteins 9

Mitochondrion Energy H2O Known as the “powerhouses” of the cell because they convert energy in food molecules to energy the cell can use to carry out its functions Responsible for cellular respiration Add this to your outline 10

Endoplasmic Reticulum The ER transports proteins and other materials throughout the cell spots on this organelle are ribosomes, which produce proteins similar to the system of hallways in a building. Add to your outline: Rough ER: contains ribosomes Smooth ER: does not have ribosomes

Golgi Apparatus (Body) Receive proteins and other newly formed materials from the ER, packages them, and distributes them to other parts of the cell. 12

Lysosomes Break down large food particles into smaller ones Break down old cell parts so they can be reused (like the recycling center) 13

Chloroplast Green structures typically found in plant cell to make food by photosynthesis. Captures energy from sun-light and changes it to energy the cell needs to make food. O₂ Glucose 14

Vacuole Type of sac that stores water, food, and other materials needed by the cell. Vacuoles in plants cell are larger than those in animal cells. Vacuole 15

Comparing Plant and Animal Cells Plant cells have a larger vacuole for more storage. Plants have chloroplasts for carrying out photosynthesis. Plants have cell walls for shape & support.

Name That Part Chloroplast Cytoplasm Mitochondria Nucleus Cell Membrane Lysosome Golgi Apparatus Endoplasmic Reticulum Cell Wall Vacuole Ribosomes 17

Compare a cell to a school Compare a cell to a school. For each organelle, describe something in the school that would perform that same function. Include nucleus, mitochondria, chloroplast, endoplasmic reticulum, lysosomes, vacuole, cytoplasm, cell membrane, cell wall

Types of Cells

Types of Cells Not all cells are the same. Cells with different structures perform different functions. Both plants and animals have specialized cells that perform specific functions.

Organization of Life Cells- smallest basic unit of life Tissues- a group of cells that perform a function Organs- a group of tissues Organ systems- a group of organs Organism

Types of Tissues Epithelial Connective Muscle Nervous

Epithelial Tissue Tissue that covers internal or external surfaces of an animal’s body They may consist of single or many layers. Cells are packed tightly together with little space between. Classified by shape and function. Examples: skin, linings of internal organs, blood vessels

Connective Tissue Connects and supports other tissues. Cells are often spaced farther apart. Examples include blood, bone, cartilage, ligaments, tendons, adipose

Blood Tissue that carries oxygen, nutrients, removes wastes, and fights infection. Made of red blood cells, white blood cells, and platelets. Red blood cells contain a protein called hemoglobin that attaches to oxygen molecules.

Red Blood Cells Shaped like flattened disks. Do not contain nuclei. Most numerous cell in the body.

Blood White blood cells can move in and out of blood vessels to fight infection. Larger but fewer in number than red blood cells. Body can increase production when an infection occurs.

White Blood Cells

Blood Platelets are tiny, oval-shaped cells that help blood form clots. Stick together when blood vessels break. Are constantly being replaced.

Platelets

Bone A rigid connective tissue made mostly of calcium. Provides shape and support, protection, and allow the body to move. Compact bone- hard, strong outer covering. Spongy bone- mesh-like center of bones that contains marrow.

Which is compact? Which is spongy? Bone Which is compact? Which is spongy?

Adipose Tissue A loose connective tissue also called fat. Stores energy, cushions and insulates the body. Found beneath the skin and around internal organs.

Adipose Tissue

Other Connective Tissues Cartilage is a tough, flexible tissue that covers the ends of bones. Ligaments are fibrous, slightly stretching tissues that connect bones at a joint. Tendons connect muscles to bones and allow movement.

Ligaments, Tendons, and Cartilage

Muscle Tissue Tissues that contract and relax to allow the body to move. Three types: skeletal, smooth, cardiac Skeletal attaches to bones. Smooth is found in internal organs. Cardiac is found in the heart. Skeletal muscle is voluntary and striated (striped).

Muscles

Nervous Tissue Neurons (nerve cells) are the basic unit of the nervous system. Form the brain, spinal cord, and other nerves. Controls the body and responds to stimuli.

Parts of a Neuron Cell body- contains nucleus Axon- carries messages from the cell Dendrite- receives messages from other cells.

Neurons

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