Name ______Test Date______

UNIT II - CELL STRUCTURE AND FUNCTION, VIRUSES

I. DISCOVERY OF CELLS

A. History of Microscopes

The invention and development of the microscope in the 1600’s enabled scientists to discover and study ______ – the basic

unit of structure and function in all ______things.

1.  Anton von Leeuwenhoek – was the first to try stacking several ________ together to view tiny objects. He

looked at __________________through his lenses and became known as the first scientist to describe living cells as

seen through a microscope.

2.  Robert Hooke - In 1665, he used a _______ to examine thin slices of cork and then described what

he saw and called them ________. He chose the name “cells” because the chambers he reminded him of the rooms

in the monastery.

B. Cell Theory

Nearly a century after Hooke’s findings, several other scientists discoveries led to the formation of the ______.

1. Matthias Schleiden (botanist) & Theodor Schwann (zoologist) – together they reached the conclusion that ______

________ were composed of ______.

2. Rudolf Virchow – Elaborated on Schleiden & Schwann’s proposal added “omnia cellula e cellula” : all cells come from ______

These discoveries, confirmed by other biologists, are summarized in the cell theory, a fundamental concept in Biology......

The cell theory states that:

a. All organisms are ________________

b. Cells are the smallest working units of life.

c. All cells come from _______________

II. TYPES OF CELLS

Living organisms are made of either __________or ________ cells – the two major kinds of cells

which can be distinguished by _____________.

PROKARYOTIC / EUKARYOTIC
____________; Divided into two kingdoms, _______and ____________/ All organisms other than _____________; Found in kingdoms _______, ______, ______, and ____________
________ true nucleus; Lack nuclear envelope / ___________ nucleus surrounded membrane known as nuclear envelope
Genetic material present in_____________region / Genetic material contained within_____________
_________ membrane-bound organelles / ___________ membrane-bound organelles

A. Prokaryotic Cells – All Unicellular

1. Eubacteria – “True” Bacteria; Ex. include E.coli, Streptococcus.

2. Archaebacteria – “Ancient” bacteria; live in extreme environments (salty, hot, acidic); ex. methanogens.

B. Eukaryotic Cells – Found in Unicellular and multicellular organisms

1. Protista – ex. Amoeba, Euglena, Paramecium

2. Fungi - ex. Penicillium, yeasts, molds, mushrooms.

3. Plants – ex. Mosses, ferns, flowering plants.

4. Animals – ex. Sponges, worms, snails, insects, mammals.

C. Microscopes - There are several types of modern microscopes:

1. Compound light microscope – More than one __________ uses light bent through lenses to magnify objects.

2. Electron Microscope – Uses _____________. This enhances the resolution and magnification

to allow researchers to study _____________. There are two types of electron microscopes:

a. Transmission Electron Microscope or __________- electrons are transmitted ____________the specimen; used

to study__________ cell structures.

b. Scanning Electron Microscope (SEM)- uses electrons to trace surface of the specimen; provides depth of field or 3-D view.

III. CELL BOUNDARIES

A. Cell Wall

Cell Walls are the outer most boundary in ____________, ______, and ______. They are not found in

_______. The primary function of the cell wall is to ____________.

·  Plants have cell walls made of __________

·  Fungi have cell walls made of ___________.

·  Eubacteria have cell walls made of ____________.

·  The cell walls of __________ are composed of other ____________.

B. Cell Membrane

Every cell is surrounded by the cell membrane. Its function is to maintain _________ in the cell by separating

and protecting the cell from its environment. It also regulates exchange with the environment. The cell membrane is also called the

________. It is ____________which means that it allows

some substances to pass through; acts a barrier to others.

IV. INSIDE A EUKARYOTIC CELL

Within the cell membrane, the cell is composed of the ______with its corresponding structures, the

_______and ______. The cytoplasm includes all the rest of the

material inside the cell membrane. The cytoplasm includes two components:

______– a semi-gelatinous substance that contains dissolved nutrients and wastes

______– means “little organs”. Each has a specific role in the overall function of the cell.

CELL ORGANELLES

Illustration / Structure / Type of Cell / Characteristics & Function
/ Nucleus / ______of the cell. Contains most of cell’s DNA; stored as ______, which is ______wrapped in ______.
Nucleolus / Small, dense region in the nucleus. Involved in the synthesis of ______which are required for protein synthesis.
Nuclear Envelope / Double membrane, each consisting of a ______
______. Perforated by nuclear ______which allow ______to leave the nucleus
/ Ribosomes / Tiny, non-membrane bound organelles located on ______(bound) or suspended in ______(free). Free ribosomes help manufacture ______that will stay in the cell; bound ribosomes help make proteins that will be transported out of the cell.
/ Rough Endoplasmic Reticulum / Extensive network continuous with ______. Called “rough” due to presence of ______all along the membrane. Function of the rough ER is to ______and transport ______. Most of these proteins are packaged into ______(bubbles or sacs made from membrane) and shuttled to the ______
/ Smooth Endoplasmic Reticulum / Similar to rough ER in structure, except that it lacks ______. Smooth ER functions in the synthesis of ______, metabolizes ______, detoxifies ______and ______. Also stores ______needed for muscle contractions.
/ Golgi apparatus / Flattened, round sacs that look like a stack of ______. Receives, modifies, and ships products by way of ______into the ______.
/ Lysosome / Found in ______cells only?? Membrane-bound sacs containing ______that breakdown ______and ______used cell components. Also used as defense against ______and ______
/ Vacuole / Sacs that may be used as ______for water, ions, wastes. Plants have a large central vacuole.
/ Mitochondria / Double-membrane organelle with inner folds called ______. Uses ______to manufacture energy in the form of ______. Mitochondria have their own ______.
/ Chloroplast / Found in ______cells. Contain green pigment called ______and their own ______. Chloroplasts harvest energy from the ______to produce ______through ______.
/ Centrioles / Found only in ______cells. Bundles of ______that play a role in ______.
/ Cytoskeleton / Network of ______fibers known as ______and ______. Anchor ______and provide ______. Also provide motility for some cells in the form of ______or ______. More extensive cytoskeleton found in ______cells.

VI. THE PROKARYOTIC CELL

VII. THE EUKARYOTIC CELL