Day 1

Cells What do we know about cells? Smallest unit of life Come in all shapes and sizes What we know about them is called “Cell Theory” Living things made from one or more cells Cells basic units of structure and function in living things (building blocks of living) New cells only made from existing cells.

Different types of cells

2 Major types of Cells

2 Major types of Cells Prokaryotes Eukaryotes Complex Smallest/Simplest Single Celled (unicellular) NO Nucleus No organelles Has Singular circular DNA Has ribosomes Has Cell wall that surrounds a cell membrane Complex Uni or multicellular HAVE Nucleus Helical DNA located in nucleus Many organelles that do specific jobs for cells to function. Cell membrane with some having cell wall

Additional Info Prokaryotes Eukaryotes Some have capsid around cell wall Flagella – tail-like structure motility Pilus (Pili) – hair-like structures around bacteria Helps with attachment to host or reproduction 3 Shapes Bacillus – rod Coccus – round Spirilum -spiral Eubacteria and Archaebacteria Cilia – hair like structures around cells Motility Moving substances across their surfaces Flagella Plantae, Animalia, Fungi, and Protista

2 Major Types of Eukaryotes Animal Plant

Organelles Plasma membrane - barrier surrounds cell and separates outer from inner. Cytoplasm- jelly material inside the cell’s plasma membrane. cytoskeleton network of protein fibers that provide framework for cell within cytoplasm. nucleolus – houses DNA produces ribosomes. lysosome - vesicle that uses enzymes to digest excess or worn-out cellular substances. Nucleolus Cytoplasm Lysosome Cytoskeleton Cell Membrane

ribosome -helps make proteins. endoplasmic reticulum -folded membrane system that produces protein (Rough ER) and lipids (Smooth ER). Golgi apparatus tubular membranes that modifies, sorts, and packages proteins into vesicles and transports them to other organelles or out of the cell. centriole – helps in cell division; made of microtubules. Mitochondrion – makes energy (ATP) for cell by process of cellular respiration

Rough ER Nucleolus Nucleolus Nucleolus Mitochondria Smooth ER Centrioles Golgi Apparatus Ribosome

Features in plants only Chloroplast -captures light energy and converts it to chemical energy through photosynthesis. cell wall - in plants, rigid barrier that surrounds outside of plasma membrane; made of cellulose, and provides support and protection to the cell. vacuole – stores of materials such as food, enzymes, and wastes. Vacuoles Chloroplast Cell Wall

Which cell is which?

Viruses How are viruses different from living cells? Segments of nucleic acids contained in a protein coat. Not cells Replicate by infecting host cells and using the host DNA to make more viruses. Do not grow, do not have homeostasis, and do not metabolize. Smaller than prokaryotic cells.

Why are viruses important? Pathogens- agents that cause disease. Viruses are often restricted to certain kinds of cells. Ex. HIV infects immune cells of animals. Ex. Bacteriophages- viruses that infect bacteria.

Structure Capsid- the virus protein coat. contain either RNA or DNA, but not both. Envelope- membrane surrounding capsid. Helps virus enter cell. Glycoproteins- proteins with attached carbohydrate molecule, derived from host cell. Glycoproteins

Replication – 2 Types Lytic cycle- viral infection, then replication, and then cell destruction. Once cell is destroyed, the viruses are then released. Lysogenic cycle- virus stays inside cell but do not make new viruses. Viral gene is inserted into the host chromosome which is called a provirus. When the cell divides the provirus divides. Virus replicated without destroying cell. example: Herpes virus

Viral Shapes Spherical Helical Rod Shaped Polyhedral

Bacteriophage Structure

Size comparison