Bio: 3.1-3.6 - Cells

Cell Theory

Cell Theory

1. All organisms are made of 1+ cells

2. The cell is the basic unit of structure & function in a living thing (atoms -> biomolecules -> organelles -> cells -> tissues -> organs -> organ systems)

3. New cells are made from existing cells

Prokaryote

mostly unicellular bacteria w/ 1 strand of DNA floating as a nucleoid, has no complex organelles and usually asexually reproduces

Eukaryote

Mostly multicellular organisms, usually larger and has a nucleus w/ complex membrane-bound organelles, some fungi, mostly sexually reproduces

All cells have

cell membrane, cytoplasm, DNA, ribosomes

Endosymbiotic Theory

complex, eukaryotic cells arose from prokaryotic cells

Endosymbiotic Theory Process

1. Prokaryotes existed first 2. In some prokaryotes, the membrane folded inward to make pockets 3. Infolded cell membrane surrounded DNA to make nucleus 4. Some primitive eukaryotes engulfed prokaryote (became mitochondria & created animal cells) 5. Some animals cells engulfed photosynthetic prokaryote (became chloroplast and created plant cells)

Evidence supporting Endosymbiotic Theory

mitochondria and chloroplasts have 2 membranes, their own DNA & ribosomes (same size and shape), and are autonomous (grow & divide on their own like bacteria)

Animal Cells

no cell wall and chloroplast, round-shaped, has centrioles and some have cilia and flagella, has many, small vacuoles, can move

Plant Cells

has cell wall and chloroplast, box-shaped, no centriole, cilia, or flagella, one large vacuole

Nucleus

stores DNA and regulates cellular activities

Nucleolus

produces and assembles ribosomes

Cell Membrane

Surrounds the cell and regulates what molecules can enter & exit the cell

Cell Wall

Provides external support and protection to plants - made of cellulose

Cytoplasm

Fills up the spaces between the organelles

Ribosomes

Produces proteins (rib -> protein)

Rough ER

Produces and stores secretory proteins w/ its ribosomes and bumpy tubes

Smooth ER

Produces and stores lipids w/ its flat tubes (smooth as butter)

Golgi Apparatus

Modifies proteins & sends them throughout the cells in vesicles (vesicles = vehicles)

Vacuole

Storage of substances like water & food; many, small in animals, 1 large in plants

Lysosome

Breaks down cellular waste using enzymes; many in animals, some in plants (lysol = cleans)

Mitochondria

Produces energy by breaking down sugars (cellular respiration) POWERHOUSE

Chloroplast

Uses sunlight to produce sugars (photosynthesis)

Cytoskeleton

A network of fibers that provides internal support & roads for vesicles and organelles to attach to

Centrioles

Assists w/ cell division (twizzlers divided into strands)

Cilia <3

Short hairs that help with cellular movement/the movement of fluids (like mucus...)

Flagella

a long tail-like structure that aids in cell movement

Bacteria Cell

Prokaryotic cell w/ a cell membrane & wall, cytoplasm, ribosomes, cytoskeleton, and sometimes flagellum

Fungi Cell

Eukaryotic cell w/ cell wall, but no chloroplast (has both animal and plant cell properties)