Cells – Chapter 1

Cell

• The smallest unit that can perform all the processes necessary for life.

The Cell Theory

• All organisms are made of one or more cells.

• The cell is the basic unit of all living things.

• All cells come from existing cells.

Why are cells so small?

• There volume is limited by how much material can to get into the cell to keep it alive.

• This is referred to as the “surface area to volume ratio”.

Types of cells

• Prokaryotic Cells – Cells that do not have their DNA contained in a nucleus.

• Eukaryotic cells – Cells that have their DNA contained in a nucleus.

An Organism is…

… a complete living thing.

Unicellular organism – A complete living thing made of only one cell.

Multi-cellular organism – A complete living thing made of more than one cell.

Types of organisms

• Prokaryote – An organism that is made of a cell whose DNA is not contained in a nucleus.

• Eukaryote – An organism that is made of cells whose DNA is contained in a nucleus.

Prokaryotic Cell

Prokaryote

Eukaryotic Cell

Eukaryote

Cell Membrane

• A protective barrier that encloses a cell and acts as a barrier between the inside of a cell and the cells environment.

Cytoplasm

• The jelly-like fluid found inside of cells that the organelles “float” in.

Organelles

• Small bodies in a cell’s cytoplasm that are specialized to perform specific functions.

Nucleus

• The Organelle that contains the cells DNA (the genetic material) and is the control center of the cell.

Ribosome• The organelle in which amino

acids are hooked together to make proteins.

Endoplasmic Reticulum• The organelle that makes lipids, breaks

down drugs and other substances, and packages proteins for Golgi complex.

They also help to transport things throughout the cell. (serve as a delivery system)

Mitochondria

• The organelle that breaks down food molecules to make ATP (energy) needed to power the various processes in the cell.

Chloroplast• The organelle that uses

the energy of sunlight to make food in a process called photosynthesis.

• The food is called glucose.

• Found in plant cells.

Golgi Complex

• The organelle that processes and transports proteins and other materials out of the cell.

Vesicle

• A small sac that surrounds material to be moved into or out of a cell.

Vacuole

• The organelle that stores water and other materials.

Lysosome

• The organelle that digests food particles, waste, cell parts, and foreign invaders.

Cell Wall

• A rigid/stiff structure that surrounds the cell membrane of plants, algae and prokaryotic cells and provides support.

The Organization of (multi-cellular) Living Things

• Cells – The smallest unit that can perform all life processes. (The building blocks of life)

• Tissue – A group of similar cells that can perform a common function.

• Organ – a collection of tissues that carry out a specialized function of the body.

• Organ System – A group of organs that work together to perform body functions

• Organism – A complete living thing

The Organization of living things

Structure and Function

• Structure – The arrangement of parts of an organism (what it is made up of and how it is put together)

• Function – the special, normal, or proper activity of an organ or part (it’s job or purpose)

Unicellular –vs- Multi-cellular organisms

Unicellular Organisms are made up of only one cell

Multi-cellular Organisms are made of many cells

Benefits of being Multicellular

• Larger Size – Large organisms are prey for fewer predators

• Longer Life – Life span is not limited to the life span of a single cell

• Specialization – Each type of cell has a particular job so the organism is more efficient.