unit 4 - cell biology

prokaryotic cells

- simplest, most ancient/oldest types of cell

- found only in bacteria; no nucleus and no membrane bound organelles.

eukaryotic cells

 -  more modern, complex cells 

  - contain nucleus and “membrane-bound” organelles

  - found in plants, animals, fungi, protists

Cell Membrane (Plasma membrane) FUNCTION

Outer boundary of the cell;separates the cell from the external environment Regulates what goes in or out of cell (maintains homeostasis) most important

Cytosol 

(cytoplasm) FUNCTION

Clear fluid filling the cell in which organelles are suspended

Nucleus FUNCTION

contains the genetic material; controls the activities of the cell Surrounded by nuclear membrane

Nucleolus

Found within nucleus, site where ribosomes are made

Endoplasmic Reticulum (Smooth = No Ribosomes, Rough = with ribosomes) FUNCTION

“intracellular highway”; system of transport tubules within the cell

Ribosomes (Free floating vs. Attached to E.R) FUNCTION

Location where proteins are assembled; most numerous organelle

Golgi Apparatus (FUNCTION)

Packaging and processing organelle; proteins are modified and prepared for export

Mitochondria (FUNCTION)

“Powerhouse” of the cell; location where ATP is made by aerobic respiration

Lysosome [trash disposal + digestion ] (FUNCTION)

Contain digestive enzymes, break down foods and worn out cell parts

Peroxisome [Nuclear waste dump or ”prison”] (FUNCTION)

Small, membrane bound, contain toxic peroxides that are safely broken down

Cytoskeleton [microtubules and microfilaments] → protein strands (FUNCTION)

Provides shape and support for the cell

Vacuole (FUNCTION)

Storage organelles, stores materials and wastes

Centrioles (FUNCTION)

Aid in cell division

Cell walls (FUNCTION)

Found outside cell membrane, made of cellulose; provides support

Plastids a. Chloroplasts b. Chromoplasts c. Leukoplasts (WHITE) (FUNCTION)

a. Contain chlorophyll; site of photosynthesis

b. Contain accessory pigments that aid in photosynthesis

c. Store starch

Cell Specialization

Not all cells found within an organism are similar looking.  Many cells have a specialized structure that enables them to better carry out their specific function.

(1665) Hooke

- first to use the term “cell” to describe the structures that make up all living things.

- Observed cork cells (dead) → Cork Oak “cells” - jail cells in monetary

(1670’s) Leeuwenhoek

- father of modern microbiology

- first to observe living cells

Cell Theory

1. All organisms are composed of one or more cells

2. Cells are the basic units of structure and function

for all living things

3. Cells arise only from other pre-existing cells

large central vacuoles

plants cells

do eukaryotic or prokaryotic contain genetic material?

both

contains DNA in a loop (plasmid)

prokaryotic cells

example is bacteria cells

prokaryotic cells