Unit 2: Basic Biological Principles Explain the characteristics common to all organisms. Compare the structure and function of prokaryotic and eukaryotic cells. Describe and interpret relationships between structure and function at various levels of biological organization (ie., organelles, cells, tissues, organs, organ systems, and multicellular organisms).

What is Biology???? Can you think of any branches of biology? Biology is the study of all forms of life. There are many branches of biology which study more specific organisms or biological functions. For example… Botany  study of plants Zoology  study of animals Microbiology  study of microorganisms (bacteria/protists) Can you think of any branches of biology?

What type of living things exist? Biodiversity = the variety of life OR different types of living things Biodiversity generally increases from the poles to the equator. Biodiversity is greater in areas with consistently warm temperatures. What are the different types of living things? Plants Animals Fungi Protists Bacteria Biodiversity is greater closer to the equator.

Where do all organisms live? All living things can be found in the BIOSPHERE. The biosphere includes all living things and all the places they are found. The biosphere includes all organisms found in: Land (terrestrial) environments Water (aquatic) environments Atmosphere Can you name organisms that are found in each part of the biosphere? biosphere = everywhere life exists

What do you call specific types of organisms? A species is one particular type of living thing. Members of a species can interbreed to reproduce. There are about 2 million different living species that have been identified = a lot of biodiversity!! Where are most species located???? Are we still discovering new species???

What does it mean to be alive? An organism must contain ALL of the following characteristics to be considered “living”! Made of cells (one or many) Obtains energy (to fuel metabolism = all processes that break down substances and build new substances) Reproduces and passes on DNA to offspring Grows and develops Exhibits homeostasis (constant internal conditions) Responds to environment and/or stimuli Adapts and evolves (DNA changes over many generations)

Cell Theory The Cell theory has three principles: 1. All organisms are made of cells. 2. All existing cells are produced by other living cells. 3. The cell is the most basic (smallest) unit of life.

What do ALL cells have in common? Cells are the smallest, most basic unit of life. There are two types of cells that make up all living things…eukaryotic cells and prokaryotic cells. All cells have common components: Cytoplasm DNA (Genetic material) Plasma (cell) membrane Ribosomes

Prokaryotic vs. Eukaryotic Cells Prokaryotic Cells NO nucleus NO membrane enclosed organelles DNA floating in cytoplasm extremely small microscopic size ex. bacteria Eukaryotic Cells nucleus membrane enclosed organelles DNA in the nucleus small microscopic size ex. plants, animals, protists, fungi

Name That Cell

Endosymbiosis A theory that early eukaryotic cells were formed from simpler prokaryotes. Some organelles, such as mitochondria and chloroplasts, are believed to have once been prokaryotes that have evolved to now exist inside eukaryotes.

Cell Organelles Cell organelles are tiny structures located inside cells that carry out specific functions. Are cell organelles alive? NO What are cell organelles made from? Biological Macromolecules Carbohydrates Proteins Lipids Nucleic Acids

Cytoskeleton A network of fibers that provides internal structure and support for a cell. There are three main types of fibers which form the cytoskeleton. These fibers are made of proteins. The three types of fibers are: Microtubules – long hollow tubes that give a cell its shape Intermediate filaments – small fibers that give a cell its strength Microfilaments – tiny threads that allow a cell to move and divide

Cell membrane Also known as the plasma membrane Made of a double layer of phospholipids with proteins embedded to assist with the transportation of molecules Forms a boundary between the cytoplasm and the outside of a cell and controls what enters and exits the cell

Cytoplasm Jelly-like substance inside a cell that contains the cell organelles. It is made mostly of water and building blocks like amino acids, nucleotides and simple sugars.

Nucleus Stores and protects the genetic information, or DNA, of a cell. DNA is located in chromosomes inside the nucleus. Is surrounded by a nuclear envelope, or nuclear membrane, that contains pores that allow molecules to travel in and out of the nucleus. Contains the nucleolus which produces ribosomes for the cell.

Endoplasmic reticulum (ER) The Endoplasmic Reticulum (ER) is a network of thin folded membranes that assists in the processing and transportation of proteins and lipids. Rough ER – Produces, processes and transports proteins (roughness is the attached ribosomes) Smooth ER – Processes and transports lipids

Ribosomes The site of protein synthesis (production). Ribosomes are made in the nucleolus and can be found floating freely in the cytoplasm or attached to the Rough ER. Ribosomes are responsible for linking amino acids together to form proteins.

Golgi Apparatus (Golgi Bodies, Golgi Complex) Closely layered stacks of membrane-enclosed spaces. The spaces within the Golgi apparatus are where proteins are modified, sorted and packaged.

Vesicles Small membrane-bound sacs that isolate and transport specific molecules (such as proteins and lipids).

Mitochondria Supplies energy for the cell in the form of ATP. It is the location inside a cell where cellular respiration (conversion of food to energy) occurs. Mitochondria have their own ribosomes and DNA, which make them a unique organelle (they were once believed to be prokaryotes).

Vacuole Fluid-filled sac used for the storage of water, food molecules and enzymes. Animal cells contain multiple small vacuoles and plant cells contain one large central vacuole which helps support the cell.

Lysosomes Organelle that contains enzymes that break down damaged or worn-out cell parts, breakdown large molecules, and protect cells from invading bacteria and viruses. They are found in large numbers in animal cells.

Centrioles Cylinder-shaped organelles made of short microtubules arranged in a circle. The centrioles are perpendicular to each other and divide DNA during cell division. Centrioles also organize microtubules to form cilia and flagella (structures used for movement). Most commonly associated with animal cells.

Chloroplasts Organelles that contain an outer membrane, as well as an inner membrane that contains stacks of disc-shaped sacs called thylakoids. The thylakoids contain chlorophyll and perform photosynthesis.

Cell Wall A rigid layer found in plant cells that provides protection, support and shape to the cell. In plants and algae the cell wall is made of cellulose (polysaccharide….a.k.a. carbohydrate). In fungi the cell wall is made of chitin.

Plant Cell Animal Cell Large, central vacuole Chloroplasts Rigid cell wall outside of cell membrane No large, central vacuole No chloroplasts No rigid cell wall

Unit 2: Basic Biological Principles Continued Describe and interpret relationships between structure and function at various levels of biological organization (ie. Organelles, cells, tissues, organs, organ systems, etc..)

Organelles  Cells  Tissues  Organs  Organ Systems  Organisms Cell Differentiation Although all somatic cells contain the same DNA they may perform different functions in an organism. This is due to a process called cell differentiation, in which a cell will develop into its mature form based on the DNA (genes) that is expressed (read). Cells that perform similar functions are called tissues. Tissues that work together to perform specific functions are called organs. Organs that work together to perform specific functions form an organ system. Organelles  Cells  Tissues  Organs  Organ Systems  Organisms