Cell Structures and Functions

By: Katy Nichols and Corey Huffman

Cell Discovery

• In 1665, Robert Hooke theorized the existence of cells.

• In 1838 and 1839, two men, Matthias Schleiden and Theodor Schwann, developed the cell theory. – 1) All organisms are made up of

one or more cells.– 2) Cells are the units of life,

smallest things considered “living.”• In 1885, Rudolf Virchow added the

third statement of the cell theory.– 3) Cells divide from other cells.

Robert Hooke’s Microscope

Animal Cell Structures

• Cell Membrane

• Cytoplasm

• Organelles

• Cell Nucleus

Plasma (Cell) Membrane

While small molecules such as water, oxygen, and carbon dioxide diffuse freely across the plasma membrane, the passage of many larger molecules, including amino acids and sugars, is carefully regulated. Specialized transport proteins accomplish this task. The transport proteins span the plasma membrane, forming an intricate system of pumps and channels through which traffic is conducted. Some substances swirling in the fluid around the cell can enter it only if they bind to and are escorted in by specific transport proteins. In this way, the cell fine-tunes its internal environment.

• Containment and Separation

• Material Exchange (homeostasis)

• Information Detection

• Identification

• Attach and Reinforce cell

• Movement

• Metabolism

Cytoplasm

• Contains water, salts, organic molecules, and metabolic enzymes

• Contains Organelles• Provides a medium for

molecular movement within a cell

Other Organelles You will be introduced to in this unit

• Golgi Apparatus• Endoplasmic

Reticulum• Vacuoles• Ribosomes• Mitochondrion• Cytoskeleton• Lysosomes

Golgi Apparatus

Modifies, sorts, and packages cell

products

Endoplasmic Reticulum

• Segregates proteins to be secreted.

• Site of membrane synthesis.

Vacuoles

Stores fluid, food, and pigment.

Ribosomes

• Make Proteins.• You can find them

floating in the cytoplasm or attached to the endoplasmic reticulum

Mitochondrion

• Uses food to make ATP (energy)

• They make this energy in the process of cell respiration.

Cytoskeleton• 1. Microtubules

– Help a Cell hold shape– Form Spindle for Chromosome

separation during cell division.– Examples include:

• Centrioles– Organize Microtubules

and basal bodies for cilia.• Cilia and Flagella

– Move cells and fluid past cells.

• 2. Intermediate Filaments• 3. Microfilaments

– Move cell and change cell shape.

Lysosomes

Digest food and worn-out cell components.

Nucleus

• Nuclear Envelope– Separates

chromosomes from cytoplasm.

• Chromosomes– stores genetic

information.• Nucleolus

– Produces Ribosomes

Plant Cells

Plant cells are fundamentally the same as animal cells, except they have:

• A Cell Wall

• Chloroplasts

• Plastids

• A larger Vacuole

Cell Wall

• Surrounds, supports, and protects the cell.

• Only found in plant cells

Chloroplasts

• Carry out Photosynthesis

• Only found in autotrophs

Plastids

• Make and store food.

Plant Vacuoles

• Provides rigid structure for plant cells.

• They might store food or any number of nutrients the cell/organism need to survive.