Cytology Chapter 5.1: Cell Structure and Function

Study Notes

Objectives:
- Relate modern cell theory to changing models
- Compare unicellular, multicellular, and colonial organisms
- Differentiate between prokaryotic and eukaryotic cell structures
- Illustrate a typical cell and describe its parts' functions

What does a cell do?
- Cells, as the fundamental units of living things, perform all the functions of living things: growth, movement, reproduction, and responding to the environment.

Spontaneous Generation: Living things form from nonliving materials.
Preformation: Eggs and sperm contain miniature versions of people that grow in size.

1665: Robert Hooke names "cells" after observing cork under a microscope.
1682: Antonie van Leeuwenhoek discovers blood, sperm, bacteria, and larvae are made of cells. He also found each cell has a central part.
1831: Robert Brown names the nucleus.

Unicellular: Made of a single cell, capable of independent function. Examples: Bacteria, protozoans, some algae, and fungi.
Colony: Single-celled organisms that form a colony to work together but can also function independently. Examples: Single-celled organisms.
Multicellular: Made of two or more cells interdependent on each other for function. Highly specialized cells cannot function on their own, and need other cells to support them, to function. Examples: Plants, animals, and some algae and fungi.
- Multicellular organisms organize cells into tissues (groups of similar cells with a specific function). Tissues combine to form organs (structures with multiple tissues working together). Organs combine to form organ systems (multiple organs working together to achieve a shared function)

An organelle is a specialized structure within the cytoplasm of a cell. It performs specific functions essential for the cell's survival. Students should study the names and functions of organelles.

Eukaryote: Organisms with cells containing a true nucleus and membrane-bound organelles.
Prokaryote: Organisms with cells that lack a true nucleus and membrane-bound organelles.
- Karyote: Derived from the Greek word meaning "central part" (the nucleus).
- Eu: Means "true"
- Pro: Means "before"

Bacterial Cell (Prokaryote): Features include cytoplasm, cytoskeleton, flagellum, nucleoid, and capsule.

Plant Cell (Eukaryote): Features include chloroplast, leucoplast, cell wall, central vacuole, ribosomes, smooth endoplasmic reticulum, rough endoplasmic reticulum, and granum.

Animal Cells (Eukaryote): Features include a nucleus, nucleolus, chromatin, cilia, centrosome, cell membrane, lysosome, Golgi apparatus, and mitochondrion (as well as the other organelles).