Cells

Common Cell Traits

Cells come in different sizes and shapes. All cells have a cell membrane which is an

outer covering that controls what comes into and out of a cell.

All cells have cytoplasm which is a gelatinlike material.

Only plants, algae, fungi, and bacteria have cell walls.

Cell walls are tough, rigid outer coverings that protect the cell and give it shape.

Nucleus of a Cell The nucleus is the control center of the cell

because it holds all the genetic material which tells the cell what to do.

It is protected by a membrane called the nuclear membrane.

The nucleolus is inside the nucleus and this is where ribosomes are made.

Organelles in the Cytoplasm Organelles are tiny cell structures which

carry out specific functions within the cell.

Examples include the Mitochondria,ribosomes, endoplasmic reticulum, golgi bodies, chloroplasts, vacuoles, lysosomes.

Mitochondria Mitochondria are rod-shaped organelles

known as the “powerhouses” of the cell. They convert energy in food molecules to energy the cell can use to carry out its functions.

Ribosomes Ribosomes are very small grainlike

structures that function as factories to produce proteins.

They may be attached to the endoplasmic reticulum or they may float in the cytoplasm.

Endoplasmic Reticulum(ER)

The endoplasmic reticulum(ER) is a series of folded membranes or passageways that carry proteins and other materials from one part of the cell to another.

It may be rough or smooth. The smooth ER has no attached ribosomes. The rough ER has attached ribosomes.

Golgi Bodies The Golgi bodies are stacked, flattened

membranes which receive proteins and other newly formed materials from the ER, package them, and distribute them to other parts of the cell.

Golgi bodies are like the UPS.

Chloroplasts Plant cells have chloroplasts which are

green organelles that capture the energy from sunlight and use it to make food.

Chloroplasts make leaves green.

Vacuoles Vacuoles are the storage areas of cells. Most plants have one large vacuole while

animal cells may have one, more than one, or no vacuoles.

Vacuoles stores food and other materials needed by the cell.

They also store waste.

Lysosomes Lysosomes are small, round structures

containing chemicals that break down certain materials in the cell.

Lysosomes are the cell’s cleanup crew.

Cytoskeleton Microtubules and Microfilament both make

up the cytoskeleton framework. They both support the cell.

Levels of Organization Cells Tissues Organs Systems Organism