Biology I. Chapter 7

Biology I

NOTEBOOK #1

Are All Cells Alike?

• All living things are made up of cells. Some organisms are composed of only one cell. Other organisms are made up of many cells.

• 1. What are the advantages of a

one-celled organism?

• 2. What are the advantages of an

organism that is made up of many cells?

Discovery of the Cell

1. Robert Hooke - Observed a piece of cork and saw

thousands of empty spaces. Coined the “cell”

because they reminded him of the small rooms

in the monastery.

2. Anton van Leeuwenhoek - first person to observe

living cells.

3. Matthias Schleiden - All plants are made of cells.

4. Theodor Schwann - All animals are made of

cells.

5. Rudolf Virchow - New cells come only from other

cells.

The Cell Theory

1.All living things are composed of cells.

2.Cells are the basic units of structure

and function in living things.

3.New cells are produced from existing

cells.

Microscopes

• Compound light microscope - uses two

lenses to focus on an image through which

light passes through.

• Transmission Electron Microscope (TEM) -

sends a beam of electrons through a

microscopic slice of a specimen.

• Scanning Electron Microscope (SEM) - sends

a beam of electrons over the surface of an

object to produce a 3-D image.

Prokaryotes

• They are cells that have genetic

material that is not contained in a

nucleus.

Eukaryotes

• Usually larger and more complicated than

prokaryote cells.

• Contain a nucleus in which their genetic

material is separated from the rest of the

cell.

• Contain dozens of structures and internal

membranes.

Prokaryotic Cell Cell membrane Cell membrane Cytoplasm Cytoplasm Nucleus Organelles Eukaryotic Cell

Prokaryotic and

NOTEBOOK #2

1. What were the following scientists

credited with:

• Hooke, Leeewenhoek, Schleiden,

Schwann, Virchow

2. What are the three kinds of microscopes?

3. What is a prokaryote?

NOTEBOOK #3

Division of Labor

• A cell is made up of many parts with different functions that work together. Similarly, the parts of a computer work together to carry out different functions.

• Working with a partner, answer the following questions. • 1. What are some of the different parts of a computer?

What are the functions of these computer parts? • 2. How do the functions of these computer parts

correspond to the functions of certain cell parts? Interest Grabber

Comparing the Cell to a Factory

• The cell is made up of many tiny structures that act similar to specialized organs.

• The structures are known as organelles.

• Biologist split the eukaryotic cell into two parts:

• Nucleus • Cytoplasm

Nucleus

• The nucleus is compared to the main office of the factory.

• It is the control center. • The nucleus contains

nearly all the cell’s DNA and with it the coded instructions for making proteins and other important molecules.

Parts of the nucleus

• The nucleus is surrounded by a nuclear envelope. • The envelope contains

many different pores that allow materials such as proteins, RNA, and other molecules to travel to and from the rest of the cell. • Just like the memos,

instructions and blueprints move in and out of the office.

Parts of the nucleus

• The nucleus contains granular material

made up of DNA bound to proteins called

chromatin.

• During cell division, this chromatin

condenses to form thread-like structures

called chromosomes.

• The nucleus also contains a small, dense

region called the nucleolus which is

Ribosomes

• One of the most

important products of the cell is the making of

proteins.

• Proteins are assembled on

ribosomes.

• Ribosomes are small particles of RNA and protein found in two places throughout the cell:

1. Endoplasmic Reticulum 2. Cytoplasm

• In the factory, they are the machines that produce the product.

Endoplasmic Reticulum

• The endoplasmic

reticulum is the site

where lipid components

of the cell membrane

are assembled, along

with proteins and other

materials that are

exported from the cell.

• There are two types of

ER’s:

1.Rough ER

2.Smooth ER

•Rough ER

• Rough ER is responsible for producing proteins that are exported from the cell.

• It is called rough because there are ribosomes found on the surface of the ER which gives it a bumpy surface.

• The proteins made by these ribosomes enter the ER where they are

• Smooth ER

• Ribosomes are not found on its surface.

• Contains enzymes that perform

specialized tasks such as the synthesis

of membrane lipids and the

detoxification of drugs.

• Liver cells have large amounts of

smooth ER.

NOTEBOOK #4

1. What is the nucleus? 2. What is it surrounded by? 3. What is found in the nucleus? 4. What is the job of the ribosomes? 5. Where are the ribosomes found? 6. What is the job of the ER?

7. What are the two kids of ER and explain the difference.

Golgi Apparatus

• They are a stack of apposed membranes.

• The function of the golgi apparatus is to modify, sort, and package proteins and other materials from the ER for storage in the cell or secretion outside the cell. • Golgi is the customization

shop where the finishing touches are put on the product.

Lysosomes

• They are small organelles filled with enzymes. • They have two major jobs:

1. Digest or breakdown lipids, carbohydrates, and proteins into small molecules that can be used by the cell.

2. Ingest and destroy old and worn-out organelles.

• The lysosome can be compared to the cleanup crew of the factory.

Vacuoles

• Vacuoles are the storage area of the cell.

They store things such as water, salts, proteins, and carbohydrates. • In plants, there is usually a large central

vacuole that is filled with liquid. The

pressure built up in the vacuole make it

possible to support heavy structures.

• In single-cell organisms, such as the paramecium, they contain a contractile vacuole that pumps out excess water to help maintain homeostasis.

• Homeostasis is the maintenance of a controlled internal environment.

NOTEBOOK #5

1. What is the gologi apparatus?

2. What is the job of the golgi apparatus? 3. What are lysosomes?

4. What is the job of the lysosome? 5. What is a vacuole?

6. What is the job of the vacuole?

Mitochondria

membranes - an outer membrane and an inner membrane that is folded up to create more surface area. • Mitochondria are inherited

from the cytoplasm of the ovum, or egg.

• Called the “Powerhouse” of the cell.

Chloroplasts

• C

hloroplasts are

organelles that capture

the energy from sunlight

and convert it into

chemical energy in a

process called

photosynthesis.

• They act as solar panels.

The chemical that

absorbs the sunlight is a

green pigment called

Organelle DNA

• Mitochondria and Chloroplasts contain their own genetic information in the form of small DNA molecules.

• They are believed to be descendants of ancient prokaryotes.

• The idea suggests that the ancient prokaryotes

developed a symbiotic relationship with the eukaryotes and actually took up residence within the eukaryotic cell.

Cytoskeleton

• The cytoskeleton is a network of protein filaments that helps

the cell to maintain its shape. The cytoskeleton is also involved in movement.

• The two main types of protein filaments

• Microfilaments - thread-like structures made of actin. • Microtubules - hollow structures made of tubulins.

• Play an important role in cell division. • Make up centrioles, cilia, and flagella.

NOTEBOOK #6

1. What is the job of the mitochondria? 2. What is made there?

3. How is mitochondria inherited? 4. What is the job of the choloroplast?

5. What is the chemical that absorbs the solar energy? 6. According to the endosymbiotic theory, how did

mitochondira and chloroplasts end up living inside of cells?

Prokaryotes Eukaryotes Cell membrane Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton

Animal Cells Plant Cells

Centrioles Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell Wall

Venn Diagrams

Plant Cell Nuclear Ribosome Ribosome Smooth endoplasmic Nucleus

Rough endoplasmic reticulum Nucleolus Golgi apparatus Mitochondrion Cell wall Cell Chloroplast Vacuole

Animal Cell Centrioles Nucleolus Nucleus Nuclear Rough endoplasmic Golgi apparatus Smooth endoplasmic Mitochondrion Cell Ribosome Ribosome

Cell membrane Endoplasmic Microtubule Microfilament Ribosomes _{Mitochondrion} Figure 7-11 Cytoskeleton

NOTEBOOK #8

In or Out?

• How is a window screen similar to a cell membrane?

Read on to find out.

• 1. What are some things that can pass through a

window screen?

• 2. What are some things that cannot pass through

a window screen? Why is it important to keep these

things from moving through the screen?

• 3. The cell is surrounded by a cell membrane,

which regulates what enters and leaves the cell.

Why is it important to regulate what moves into and

out of a cell?

Cell Boundaries

• All cells are surrounded by a thin, flexible

barrier known as the cell membrane.

• The cell membrane regulates what enters

and leaves the cell and also provides

protection and support.

• Nearly all cell membranes are composed

of a double layered sheet called a lipid

bilayer.

Cell Walls

• Cell walls are present in many organisms

including plants, algae, fungi, and

prokaryotes.

• The main function of the cell wall is to

provide support and protection for the

cell.

Diffusion Through

Cell Boundaries

• Every living cell exists in a liquid

environment that it needs to survive.

• One of the most important functions of

the cell membrane is to regulate the

movement of dissolved molecules from

the liquid on one side of the membrane to

the liquid on the other side.

Diffusion Through

Cell Boundaries

• Concentration- the mass of solute in a

given volume of solution, or mass/volume.

• Diffusion- process by which molecules tend

to move from an area where they are more

concentrated to an area whe they are less

concentrated.

• Equilibrium- when the concentration of the

solute is the same throughout the system

Diffusion Through

Cell Boundaries

• Because diffusion depends upon random

particle movements, substances diffuse

across membranes without requiring the

cell to use energy.

Osmosis

• Osmosis is the diffusion of water through a selectively permeable membrane.

• Isotonic - when the concentration of two solutions is the same

• Hypertonic-when comparing two solutions, the solution with the greater concentration of solutes. • Hypotonic- when comparing two solutions, the

Facilitated Diffusion

• Movement of specific molecules across a

membrane

High Low Cell Glucose Protein

Facilitated

Notebook #8

• What are most cell membranes composed of? • What is the job of the cell membrane?

• What types of organisms have cell walls? • What is diffusion?

• What is osmosis? Define isotonic, hypertonic, and hypotonic.

Outside

Inside of cell Cell

Proteins

Protein _{Lipid bilayer}

Carbohydrate

Molecule to

Molecule Energy

NOTEBOOK #9

1. What part of the cell membrane aids in facilitated diffusion?

2. What is the structure of the cell membrane? 3. What is osmosis?

From Simple to More Complex

• Many multicellular organisms have structures

called organs that have a specific function

and work with other organs.

• Working together, these organs carry out the

life processes of the entire organism.

NOTEBOOK #10

•1.

Some activities cannot be performed by only

one person, but need a team of people. What type of

activity requires a team of people to work together in

order to complete a task?

•2. What do you think are some characteristics of a

successful team?

•3. How is a multicellular organism similar to a

successful team?

Muscle cell Smooth muscle tissue Stomach Digestive system

•

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•

Diffusion

•

Osmosis

•

Passive Transport

•

Active Transport

•

Endocytosis and Exocytosis

Interest Grabber

NOTEBOOK #11

An Important Process

• While walking along a dusty path, you begin to cough. As you continue your walk, a small insect comes flying toward you. You blink and then duck so that it misses you. These actions are just a few examples of

homeostasis. Homeostasis is the process by which organisms keep internal conditions relatively constant

1.

List three other examples of homeostasis

that occur in organisms.

2.

Why is homeostasis important to an

organism?

Homeostasis

The process by which

organisms keep internal

conditions relatively constant

despite changes in external

environment.

Water Regulation

(Osmoregulation)

Oxygen

Regulation

• Click the image to play the video segment.

Video 1

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Video 2

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Video 3

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Video 4

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Video 5

• The latest discoveries in cell study • Cell structure activity

• Career links on histotechnologists • Interactive test

• Articles on cells

• For links on cell theory, go to www.SciLinks.org and enter the Web Code as follows: cbn-3071.

• For links on cell membranes, go to www.SciLinks.org and enter the Web Code as follows: cbn-3073. Go Online

• 1. What are the advantages of a one-celled organism?

• A one-celled organism has simpler needs and can

respond immediately to its environment because its entire cell is immersed in its environment.

• 2. What are the advantages of an organism that is made up of many cells?

• In a multicellular organism, different jobs are divided

among different groups of cells that work together. Also, a multicellular organism can continue to survive even if it loses some of its cells.

• Working with a partner, answer the following questions.

• 1. What are some of the different parts of a computer? What are the functions of these computer parts?

• Answers may include: monitor (interfaces with the computer’s environment), software (instructions for how to carry out different jobs), CPU (directs the computer's activities), recycle bin or trash can (storage area for wastes), and so on.

• 2. How do the functions of these computer parts correspond to the functions of certain cell parts?

• Students should try to link the functions they described in question 1 to the functions of the different cell structures. The cell needs a way to interface with its environment (cell membrane), instructions for carrying out different jobs (DNA), and a CPU to direct the cell’s activities (nucleus).

• 1. What are some things that can pass through a window screen?

• Answers may include air, fine dust, and rainwater.

• 2. What are some things that cannot pass through a window screen? Why is it important to keep these things from moving through the screen?

• Insects, leaves, and other matter that may fall from trees. The screen keeps out annoying insects and objects that may bring dirt into the home.

• 3. The cell is surrounded by a cell membrane, which regulates what enters and leaves the cell. Why is it important to regulate what moves into and out of a cell?

• Materials such as oxygen and food that are needed by the cell have to be able to get inside the cell. At the same time, excess materials have to leave the cell.

• 1. Some activities cannot be performed by only one person, but need a team of people. What type of activity requires a team of people to work together in order to complete a task?

• Answers might include building a human pyramid or constructing an arch out of blocks.

• 2. What do you think are some characteristics of a successful team?

• Divide up jobs and cooperate well with one another.

• 3. How is a multicellular organism similar to a successful team?

• The functions of the organism are divided up among its parts (organs and organ systems). All the parts cooperate to carry out all the functions of the whole organism.

Interest Grabber Answers

1. List three other examples of homeostasis that occur in organisms. Accept all reasonable student examples that show an understanding of homeostasis.

2. Why is homeostasis important to an organism?

Homeostasis allows an organism to remain in balance with its