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VARIOUS NOTES: CELL UNIT NOTES

Cell Vocabulary Words

Organelles - The smaller parts of the cell that; produce energy, build and transport materials, and store and recycle wastes.

Cell Wall - The rigid layer of material that surrounds the plant cell giving it strength and protection. Plant cell only.

Cell Membrane - The outside boundary of the animal cell, the part next to the cell wall in a plant. In both cells, it controls what enters and exits the cell. It is semi-permeable – lets some things through.

Nucleus - The control center of the cell that directs all of the cell activities. Genetic material is contained inside. Usually found in center of cell.

Nuclear Membrane - The outside boundary of the nucleus that controls what enters and exits the nucleus.

Chromatin - In the nucleus of the cell, the genetic blueprints that carry the directions to cell parts that tells them how to work. Genetic material made of DNA.

Chromosomes - Worm like structures made up of chromatin. These form when the cell is going to divide so that all of the genetic material is copied accurately.

Nucleolus - In the nucleus, the place where the ribosomes are made. A small sack.

Cytoplasm - The gel that is the material that organelles float in which is found between the cell membrane and the nucleus.

Mitochondria - Organelles that produce most of the energy for cells. There will be lots of mitochondria in animal cells – especially muscle cells. Respiration occurs in the mitochondria.

Endoplasmic Reticulum (E.R.) - Passageways that carry proteins, etc. from one place to another. Hollow tubular structures that travel around the cytoplasm.

Ribosome - Grain-like bodies that produce proteins. (look like little dots). Is often found on E.R. so proteins can be easily transported.

Golgi Bodies - Flattened collection sacs and tubes in the E.R. that distribute proteins + release materials outside cell. Package proteins up in bubbles called vesicles so they can move through membrane. Vesicles also act as an address on an envelope so protein gets where it is supposed to go.

Chloroplasts - Organelles that capture sunlight and produce food through process of photosynthesis. Only found in plant cells. They contain chlorophyll, which is green.

Vacuoles - Round storage sacs for keeping water, food, or wastes. Plants have larger vacuoles which mainly store water, animal cells have smaller vacuoles.

Lysosomes - Round organelles containing chemicals to break down large food, old cell parts, and releases substances that can be used again by the cell. Not usually found in plant cells. How tadpoles lose tails when turning into frogs.

Photosynthesis - Chemical reaction that occurs in plant cells that converts sunlight, water and CO2 into sugar and oxygen.


Respiration - Chemical reaction that occurs in all cells. Happens in the mitochondria. Converts sugar and oxygen into energy and CO2.




CELL UNIT NOTES

I. Theory of the History of the Earth

A. 4.6 Billion years ago – 4,600,000,000 years ago

1.)Earth forms from a huge cloud of gas and dust that is pulled

together by gravity.

1.)The Earth has cooled and rocks have formed on the surface.

Volcanoes have begun erupting. The atmosphere has

developed and is filled with poisonous gases (methane, hydrogen,

nitrogen, carbon monoxide, carbon dioxide). Thunderstorms have

started to occur. Oceans have begun to form.

C. Between 3.5 and 4 Billion years ago

1.)Chemical reactions caused by lightning and UV radiation from

the sun have created the chemicals of life – Amino Acids, Proteins,

Carbohydrates, Lipids, and Alcohols. This might have occurred like Dr.

Stanley Miller’s experiment – the flask with gases and light and electricity

turned into the brown, tar like substance.

D. 3.5 Billion years ago

1.)The first cell is created. There is fossil evidence of cells this

old. They did not require oxygen – this is called an anaerobic organism.

They were also consumers – they needed food. They are called

E. 3 Billion years ago – First Cellular Evolution

1.)Cells develop that are producers – called autotrophs – can make their

own food using some materials and sunlight. This process is called

photosynthesis. The producers absorbed a great deal of carbon dioxide

and gave off a great deal of oxygen. Over millions of years this altered

F. 500 Million years ago (.5 Billion) – Second Cellular Evolution

1.)Cells developed that could use oxygen. This makes them

more efficient. They are called aerobic organisms. This allows them to

grow larger and evolve faster.

G. Further cellular evolution

1.)Cells became larger and developed organelles that

specialized on certain jobs

2.)Multicellular organisms developed – more than 1 cell large.

3.)Organisms developed that reproduced sexually – this sped up

the evolutionary process due to laws of heredity. Before this they

reproduced asexually – simply splitting in half and creating an exact

4.) A prokaryote is a single-celled organism that lacks a membrane-
bound nucleus, mitochondria, or any other membrane-bound organelles.

Ex: bacteria

5.)A eukaryote is any organism whose cells contain a nucleus and other

structures enclosed within membranes.


A. Cell Theory is the idea that all living things are made up of one

or more cells AND that cells are the basic unit of structure and

function in living things AND living cells come only from other living cells.

1. 1 cell organisms are called UNICELLULAR

2. Organisms with more than 1 cell are called

MULTICELLULAR

3. We are multicellular – an adult has around 1 trillion cells –

1,000,000,000,000 cells in their body.

4. The parts of a cell are not alive – the cell is the smallest

unit of life – just like the atom is the smallest unit of an element.

5. There is no such thing as SPONTANEOUS

GENERATION, which was a theory for many years that living

things just appeared.

III. Cell Structures – The parts that make up a cell are called

ORGANELLES. These structures serve the following functions – provide support

and protection, building an repairing cell parts, storing and releasing energy, getting

rid of waste materials, and reproduction.

1. Only found in plant cells

2. Rigid layer made up of cellulose – celery

3. Supports the cell – allows grass to bounce back after

being stepped on and flowers to grow tall. Cell walls bond with

other cell walls to form the structure of a plant.

4. Located right outside the cell membrane.

1. In both plant and animal cells

2. Animal cell membranes contain cholesterol, which gives

3. Made out of protein and fat

4. Cell membrane is SEMIPERMEABLE – allows some

5. It is the outermost layer in animal cells and right inside

6. It controls what moves into an out of the cell. It also

it more strength.

materials in and keeps others out.

the cell wall in plant cells.

keeps the organelles in the cell safe and holds them in. It is like

the skin on a person or the walls and doors of a factory.

1. Both plant and animal cell

2. Control center of the cell – tells the cell what to do,

3. Found inside the cell – usually near the center

D. NUCLEAR MEMBRANE

1. Both plant and animal cell

2. Located on the outside of the nucleus

3. Controls what goes into and out of the nucleus

4. Keeps organelles inside the nucleus from floating away

1. Both plant and animal cell

2. Located inside the nucleus

3. They appear to be wormlike pieces

4. The # of chromosomes depends on the species –

5. They are made up hundreds of GENES which are made

contains the genetic information of the cell

humans have 46 chromosomes in every normal cell

of nucleic acids

a. DNA – deoxyribonucleic acid

b. RNA – ribonucleic acid – this is the messenger of the DNA

6. Controls the cell processes and growth

7. Involved in reproduction – passing of traits from parents

1. Both plant and animal cell

2. Small sack located inside the nucleus

3. Produces the ribosomes for the cell

1. Both plant and animal cell

2. Clear, thick, jelly like substance found inside the cell

3. All of the organelles are suspended in the cytoplasm

4. Provides protection for the organelles – kind of like

5. Mostly made up of water – just like jello is mostly water

H. ENDOPLASMIC RETICULUM (E.R.)

1. Both plant and animal cell

2. A series of hollow tubular structures that goes all over the

3. Connect various organelles and allows materials to be

4. Functions like a trucking company for the cell – brings

packing peanuts

transported around and out of the cell

things in from the membrane and takes things out.

1. Both plant and animal cell

2. Small seed shaped structures located all over the

3. They are the factories of the cell – they produce the

4. The RNA carries directions from the DNA to the

cytoplasm but often connected to E.R.

proteins that a cell needs for almost every activity

ribosomes that tell the ribosomes what protein to make and how to

1. Both plant and animal cell

2. Rod like structures that are found all over the cytoplasm

3. They are the power plants of the cell

4. They break down the simple sugars or “food” and turn it

5. Sugar is combined with oxygen and produces energy,

but often near other structures like ribosomes

into energy – this process is called RESPIRATION

water and carbon dioxide

K. GOLGI BODY, APPARATUS, or COMPLEX

1. Both plant and animal

2. Located in the cytoplasm

3. Package and distributes materials throughout the cell

1. Both plant and animal cells

2. Plant cells usually have one large vacuole that stores

water. When the vacuole is full the cell is firm and plump

– the plant looks full and healthy – this is why plants shrivel up

when they are not watered.

sugars, waste, and water

3. Animal cells have several smaller vacuoles for storing

4. These sacks are located in the cytoplasm

5. Vacuoles act as storage tanks fro the cell

1. In animal cells

2. Located in the cytoplasm

3. Lysosomes are small sacs filled with a digestive

4. This enzyme is used to break down large food particles

5. It is also used to digest organelles and materials that the

6. Lysosomes are responsible for digesting the tail on a

enzyme – like your stomach acid

to smaller ones for use or storage

cell no longer needs – these materials are then recycled into

proteins by the ribosomes

tadpole as it turns into a frog!

1. Found in plant cells

2. Green sacks that are found throughout the cytoplasm

3. Contain chlorophyll which is chemical that is used in

4. PHOTOSYNTHESIS is the process where light energy

photosynthesis.

from the sun is used to turn carbon dioxide and water into sugar

and oxygen.