Download Ch. 7

Ch. 7 A View of the Cell
7.1 The Discovery of Cells – in the mid ________, Anton van Leeuwenhoek looked at the ______ cells.
He looked at bacteria in his teeth (plaque), his blood cells and pond water (and saw “animalcules”).
A. The History of the Cell Theory - ___________ microscopes, people believed diseases were caused
by evil spirits. Many other superstitions help explain unseen phenomena. The invention of the
microscope helped to discover ____________________ and paved the way for modern science.
1). Development of light microscopes- Dutch scientist Anton van Leeuwenhoek (about 1650)
developed the first simple light microscope. It contained _____ lens and used natural light.
a. ________________________________ – use a series of lenses of magnify objects (1500x)
2). The Cell Theory - Robert Hooke (1650’s) used a compound light microscope to study
___________, the dead cells of oak bark. Cells are the basic unit of life. Mattias Schleiden (1830’s)
concluded that all plants are composed of ____________ _. Theodore Schwann concluded that all
____________ __ are composed of cells.
a). __________________:
1. All organisms are composed of one or more cells
2. The cell is the basic unit of life
3. All cells come from preexisting cells
3). Development (1940’s) of ______________________________________ – uses a beam of
electrons instead of natural light to magnify structures up to 500,000 x’s
1. The Scanning Electron Microscope (SEM) – scans the ____________ of an object for a
three dimensional image (60,000x
1.
The Transmission Electron Microscope (TEM) – can see objects within the
_____________ (over 100,000 x)
2. The Scanning Tunneling Microscope (STM) – uses the flow of electrons to investigate
____________ on the surface of a molecule.
B. Two Basic Cell Types
1. ____________ – Cells with NO nucleus
or membrane-bound structures (ex:
bacteria)
2. ____________ – Cells with a nucleus and
membrane-bound organelles (plants,
animals, fungi and protests)
a). ____________ – membrane-bound
structures within eukaryotic cells
b____________ – the “control center”, or
manager, of the cell
7.2 The Plasma Membrane
A). Maintaining a Balance – living things must maintain homeostasis w/ their surroundings
1). Why cells must control materials- Cells need ____________ like glucose, amino acids, and
lipids. These materials must enter and exit the cell somehow.
a). ____________ ____________ – a boundary between the cell and its environment. Allows
material in (ex: nutrients) and out (ex: wastes) of the cell.
b). ____________________ – interstitial fluid that holds cell contents
c). ____________________ – the process of maintaining a balance with internal and external
conditions
d). ____________________ ____________________ – a process that allows some molecules
into the cell while keeping others out (ex: a pasta strainer)
B). Structure of the Plasma Membrane
a. ____________________ – lipids with a phosphate group attached to them
1). Makeup of the phospholipid protein bilayer – the
membrane is composed of hydrophilic (water loving) phosphate
heads and hydrophobic (water fearing) lipid tails. Channel
proteins serves as ______ that allow material in /out of the cell.
2. _______ _ _________ ______ – phospholipids move
through the membrane while proteins create a “mosaic” pattern.
3). Other components of the plasma membrane
a). Cholesterol helps stabilize the phospholipids
b). ______________ ___________________ –
allow needed substances or waste material to
move through the plasma membrane
7.3 Eukaryotic Cell Stucture
A. Cellular Boundaries- the cell membrane protects the cell
1. _____________ _______ – a rigid, cellulose structure located outside the plasma membrane that
provides support and protection (ex: plant cells)
a). Nucleus and cell control – the
nucleus contains many structures, such as:
b). ______________- strands of DNA
2. ____________________ – makes
____________________ which assembles proteins
3. ________________________ – Membrane
that allows material in and out of the nucleus
B. Assembly, Transport, and Storage
1. Structures for assembly and transport of
proteins
a). ____________________
____________________ – transports proteins
1). ____________________ – contains ribosomes
2). ____________________ - no ribosomes
b). ____________________ ____________________ -assemble complex proteins
c). ____________________ – store material: food, proteins, water, and waste
d). ____________________ – contain digestive enzymes which destroy damaged parts of the cell
C. Energy Transformers
3. ____________________ – plant structure
a). ____________________ - capture light energy (photosynthesis) and produce food
i). ____________________ – green chemical that traps light energy
b). ____________________ – control pigment in plants
c). ____________________ – store starch
4. ____________________ – “powerhouse” of the cell, makes energy
C. Structures for Support and Locomotion
1. ____________________ – a cell framework of tiny rods and filaments
2. Cellular support
a). ____________________ – thin, hollow protein tubes
b). ____________________ – thin, solid protein fibers
2. Cell division
a). ____________________ – use spindle fibers to pull the cell apart during replication
3. ____________________ – short, hairlike projections that move in a wavelike motion. Used
for locomotion. Ex: paramecium
4. ____________________ – longer, whiplike projections. Used for locomotion. Ex: Euglena