UNIT 3 Cells and their Structure Levels of

UNIT 3 Cells and their Structure

Levels of Organization

Cell Specialization – when a group of cells work together to perform a specific job

Human Cell Diversity

The Cell Theory is a theory that describes the properties of a cell. All living things are composed of cells 2. Basic units of structure and function in living things 3. Cells are produced from existing cells 1.

Categories of Cells Type 1 Prokaryotes Unicellular – one cell No Nucleus – DNA free floating Example – Bacteria Used in technique called Recombinant DNA

Shapes of Prokaryotes • Cocci = spherical (round) • Bacillus = (rod shaped) • Spirilla = helical (spiral)

These are prokaryote E. coli bacteria on the head of a steel pin.

Categories of Cells Type 2 Eukaryotes • Unicellular or Multicellular • Has a Nucleus • Example – Plant, Animal, Fungi, Protist

How are Eukaryotes Different from Prokaryotes Eukaryotes have a nucleus that contains DNA and Prokaryotes do not

Cell Factory

Two Types of Eukaryotes – Animal and Plant Cell Let’s take a good look at these eukaryotes!

Cell Structures in common Cell Membrane Nucleus Ribosome Endoplasmic Reticulum Vacuoles Mitochondria

Only Plant cell Structure • choroplast • Cell wall

Only Animal cell Structure • Centriole-involved in cell division • Lysosome- uses enzymes for digestion and waste removal (food particles, worn out organelles, viruses and bacteria) Garbage Collection centriole

Nucleus Controls most of cells processes Contains genetic information-DNA Chromosomes inside nucleus are threadlike structures containing genetic information

Nucleolus • Found inside nucleus • Produces ribosomes

Nuclear Envelope (membrane) • Surrounds material genetic

Ribosomes • Makes proteins for cell • Instructions come from the nucleus

Endoplasmic Reticulum • Synthesizing, packaging and transporting of proteins • Two types – rough ER and smooth ER • Network of membranes

Golgi Apparatus • Packaging system • Takes small molecules and makes larger ones then stores them

Vacuoles • Storage areas for water, salt, proteins, carbohydrates • Large structures in plants

Mitochondria • Synthesis and release of energy (Cellular Respiration) • Energy is called ATP • Powerhouse of cell

Cytoplasm • Jelly-like substance that holds organelles

Cell Membrane Regulates what enters and exits the cell Provides protection and support Semi-permeable – allows small substances through and keeps larger substances out Made of lipids and proteins

Cell Membrane (protein and lipid structure)

Cell Receptors • a protein embedded in the cell (plasma) membrane of cells • cells send and receive chemical messages constantly to coordinate the actions of distant organs, tissues, and cells. • cell growth, division, and death or opens membrane channels.

Cell Wall (Plant Only) • Provides support, protection and structure for plant cell

Chloroplast (Plant Only) • Site of photosynthesis