Unit 6 Cell Structure and Function

Objectives

Topic 1: Cell Membrane

o I can identify the component parts of the fluid mosaic model and describe their function within the cell membrane.

Topic 2: Osmosis and Diffusion

o I can describe the process of osmosis and diffusion and apply how these processes impact the homeostasis of living organisms.

Topic 3: Movement Across the Cell Membrane

o I can differentiate between passive and active transport and how each is utilized within the cell membrane.

Topic 4: Important Scientists and Cell Theory

o I can differentiate between prokaryotic and eukaryotic cells and list the three parts of the cell theory and the scientists who contributed to its development.

Topic 5: Cell Organelles

o I can identify and describe the function of all membrane bound organelles and structures found in plant and animal cells and how these changes within the cell can lead to specialization.

Important Dates:

Vocabulary Due

Quiz 1 – Vocabulary

Quiz 2 – Topics 1 through 5

LAB – Osmosis and Diffusion

Project –

Unit Test

VOCABULARY

Word Definition

Cell The basic unit of all forms of life.

Cell Theory Summary statement of all the scientific discoveries

regarding the fundamental understanding of the cell.

Prokaryote Cell membrane and cytoplasm but do not contain a

nuclei.

Eukaryote Taking small particles or molecules of liquid into the cell

through endocytosis.

Organelles Specialized structures that perform important cellular

functions.

Lipid Bilayer Tough flexible structure that forms a strong barrier

between the cell and its surroundings.

Concentration Mass or amount of a solute in a solution.

Diffusion Movement of molecules from an area of high

concentration to an area of lower concentration.

Selective Permeability This means that some molecules can pass easily while

other requires channels or added energy to pass through

the cell membrane.

Osmosis Easily allows the movement of water across the cell

membrane.

Facilitated Diffusion

When a membrane protein is used to assist in moving

molecules across the cell membrane.

Active Transport

Requires the input of energy and a protein channel to

move molecules in or out of the cell.

Endocytosis

Process of taking materials into the cell by creating an in

folding or pocket.

Exocytosis Removal of large molecules or material out of the cell.

Phagocytosis

Taking large molecules into the cell through endocytosis.

Pinocytosis

Taking small particles or molecules of liquid into the cell

through endocytosis.

Exocytosis

Removal of large molecules or material out of the cell.

Cell Specialization

Levels of organization in a multicellular organism that

includes cells, tissues, organs and organ systems.

Fluid Mosaic Model

The idea that the lipids, carbohydrates, proteins and

cholesterol that make the cell membrane are constantly

moving.

7-3 Cell Membrane, Osmosis and Transport

Parts of the Cell Membrane: (p. 184)

Diffusion vs. Osmosis:

Diffusion – Process by which molecules move from an area of high

concentration to low concentration. Diffusion will continue until equilibrium exists,

or when the concentration is equal throughout a space.

Osmosis - Movement of water through a selectively permeable membrane from

an area of low solute concentration to an area of high solute concentration. This

will continue until equilibrium is reached. The water wants to DILUTE the

SOLUTE

Type of Osmosis

Type of Osmosis Description Picture 1. Isotonic Solution

The amount of solute concentration is equal on the inside as it is on the outside.

2. Hypertonic Solution Solution outside the cell has a high concentration of solute and a low concentration of water. Water moves out of the cell = shrinking

3. Hypotonic Solution

Solution outside the cell has a low solute concentration and a high water concentration. Water moves in = turgor pressure or lyses the cell

Types of Diffusion – Movement of MOLECULES

o Simple Diffusion - passive transport of molecules across the lipid membrane.

Example: water across the cell membrane If a molecule is TOO LARGE OR Moves AGAINST the Concentration then:

o Facilitated Diffusion - passive transport that uses Proteins to conduct diffusion of molecules across the membranes. This speeds up diffusion because the molecule is too large to diffuse quickly across the cell membrane.

Example: glucose molecules = too large

o Active Transport - movement AGAINST the concentration gradient. Requires and input of energy (ATP) in order to move the molecule from an area of low concentration to an area of high concentration.

Example: sodium-potassium pump to create an electrical charge for cell function.

Diagram:

Forms of Active Transport:

Endocytosis – Process by which cells engulf substances that are much too large to enter the cell by passing through the membrane and are contained in a vesicle.

o Pinocytosis: movement of fluid particles into the cell

o Phagocytosis: movement of large food particles into the cell

Exocytosis - Exporting large molecules out of the cell. Remember the Golgi apparatus processes and packages proteins that sometimes need to by ship out of the cell.

o Proteins in the form of hormones or enzymes

REVIEW: 3 words or less!

Fluid Mosaic = ALWAYS moving

Osmosis = water movement

Isotonic = equal

Hypertonic = water in = swells

Hypotonic = water out = shrinks

Diffusion = molecules movement

Simple – passive through membrane

Facilitated – passive through channel

Active –ENERGY protein channel

Endocytosis – INTO the cell

Pino = water

Phago = food/molecules

Exocytosis = EXIT the cell

Waste or products

Diffusion Application Name___________________________Block____________________Date________ Directions: Name the physical or physiological process involved in each of the following situation. Select carefully as each answer may be used only once! Choose form the following:

1. Turgor Pressure A person soaks celery in water so the cells swell. This makes it crisp before serving

2. Hypertonic solution (water in grass leaves for salt, cells shrink and die)

A person pours salt on the grass growing in the cracks in the sidewalk and the grass dies.

3. Active Transport (against the concentration gradient requires input of energy to move molecules)

Roots of broccoli absorb calcium even when their cells contain higher concentrations of Ca than the soil solution around them.

4. Diffusion When you wake up you can smell the coffee your mom or dad is making in the kitchen.

5. Hypotonic Solution – Water moves into the cells causing them to burst

A student studying blood places some cells in distilled water; they swell and burst.

6. Equilibrium A bottle of cologne is left open soon the odor and the other gasses in the room are evenly distributed through all the parts of the room.

7. Endocytosis As they invade your body, bacteria are engulfed by white blood cells as the cell membrane closes behind them.

8. What is meant by a concentration gradient? How does it affect the rate of

diffusion? Draw a picture to explain you answer. Think about how an odor moves across a room.

Concentration gradient is the amount or concentration of molecules in one area compared to another area. Molecules are always trying to reach equilibrium so they continually diffuse or move across the gradient. For example the molecules of cologne are going to constantly move around the air until equilibrium is reached.

Osmosis Active Transport Turgor Pressure

Diffusion Equilibrium Hypertonic Solution

Hypotonic Solution Endocytosis

9. What other factors that affect the rate of diffusion? Concentration of molecules, concentration of solvent to solute, availability of protein channels and energy if needed.

10. Label the cell membrane diagram. 1 – Lipid Bilayer

a. Lipid head b. Lipid tail

2. Cholesterol signal 3. Protein Channel (Facilitated transport) 4. Carbohydrate signal 5. Protein Channel (Active Transport)

11. Answer the following: A cell takes in two substances (A and B) which are present

in concentrations lower outside the cell than inside the cell. Substance A is a large molecule needed by the cell. Substance B is a liquid droplet. Each substance enters the cell by a different process. Describe how each substance enters the cell using vocabulary from your notes.

Remember substance is lower outside than inside the cell so it WILL REQUIRE ENERGY to move the molecues into the cell. Both Substance A and B will be taken in by ACTIVE TRANSPORT. Substance A – large molecule can be taken in by phagocytosis OR active transport through a protein channel. Substance B – small liquid would be taken in by pinocytosis.

OSMOSIS and DIFFSION Define the Following:

1. Diffusion - Movement of molecules from an area of high concentration to an area of lower concentration.

2. Semi permeable membrane – The means that some molecules can pass

easily while others require channels or added energy to pass through the cell membrane.

3. Fluid Mosaic – The idea that lipids, carbohydrates and proteins and

cholesterol that make up a cell membrane are constantly moving.

4. Osmosis – Movement of water across a semi permeable membrane

Complete the table

Type of Solution ISOTONIC HYPERTONIC HYPOTONIC

Effect of a cell (choose words or use a diagram)

Remains the same Cell will shrink – lose water to the solution

Cell will swell – gain water from the solution

Freshwater protozoan such as a Paramecium must constantly pump out water to keep from bursting. What does this tell you about the solute concentration INSIDE the Paramecium compared to the solute concentration of its water environment? The paramecium is in a hypotonic solution in the water environment. The paramecium has more solute inside than the water outside has so the water move across the membrane into the paramecium. What would happen if you made the solute concentration outside the Paramecium the same as that of the inside? It would then be in an isotonic solution and it would no longer need to pump water out.

PASSIVE and ACTIVE TRANSPOT Complete the table by writing YES or NO

ACTIVE TRANSPORT

FACILITATED TRANSPORT

SIMPLE DIFFUSION

Requires energy Yes No No

Moves molecules against the concentration gradient

Yes No no

Requires a membrane protein

Yes Yes No

Sodium potassium pump is an example

Yes No no

Answer the following questions:

1. Name substances that can diffusion across the cell membrane. Water, CO2, O2, amino acids

2. Name a substance that is too large to diffuse across the cell membrane. Carbohydrates like large starch molecules and sugars

3. What prevents charged molecules from diffusion across the cell membrane? Charged molecules can’t get passed the non polar lipid tails.

4. How is facilitated transport similar to simple diffusion? They are both passive transport moving with the concentration gradient.

move without additional input of energy move from high concentration to low concentration

5. How does facilitated transport differ from simple diffusion?

Facilitated transport uses protein channels while simple diffusion

moves across the lipid Bilayer.

Osmosis Egg Lab

Beaker 1 – Syrup Solution

1. Is the syrup a hypotonic, hypertonic or isotonic solution for the egg to be placed

in? Explain your answer using the definition. What is the solute in this solution?

Syrup is a hypertonic solution which has a high solute (sugar) concentration that

will cause the water in the egg to leave for the high sugar. The egg will shrink.

2. Draw what you expect your egg to look like next class? Explain why you think it

will look like your drawing by describing what will occur to the cell, the syrup and

the fluid in the cell?

Drawing Explanation for your prediction

3. Draw what the egg actually looked like. Was your prediction correct? If not,

explain what happened since we put the egg in the syrup.

Drawing

Was your prediction correct? If not, explain what

happened.

Beaker 2 – Distilled Water Solution

4. Is the water a hypotonic, hypertonic or isotonic solution for the egg to be placed

in? Explain your answer using the definition. What is the solute in this solution?

The water is a hypotonic solution with a very low solute concentration compared

to the solutes of salts, proteins and carbohydrates that are inside the egg. The

egg will swell with the water entering the egg to dilute the solutes inside.

5. Draw what you predict will happen to the egg in this solution. Explain your

answer by describing what will occur to the cell, the water and the fluid in the cell.

Drawing Explanation for your prediction

6. Draw what the egg actually looked like. Was your prediction correct? If not,

explain what happened since we put the egg in the water after being in the syrup.

Drawing Was your prediction correct? If not, explain what

happened.

Review: Use your NOTES and VOCABULARY to answer the questions in COMPLETE

sentences.

7. What was the solvent in this experiment?Water in the egg was the solvent

in Beaker 1, Water outside the egg was the solvent in Beaker 2

8. What were the solutes?Beaker 1 – sugar in syrup Beaker 2 – protein and

carbohydrates in the egg

9. When did the egg shrink? Why?When it was placed in a hypertonic

solution because the water left to dilute the hypertonic solution.

10. When did the egg swell? Why? When it was placed in the hypotonic

solution because the water entered to dilute the higher concentration of

solutes inside.

Chapter 7: Cells Structure and Function

Part A: Cell Theory Read Section 7-1 (169 –172) in your textbook to gather the following information.

1. State the three parts to the traditional CELL THEORY:

A All living things are made of cells

B Cells are the basic unit of structure and function of all living organisms

C New cells are produced from existing cells

2. Describe what Anton van Leeuwenhoek and Robert Hooke did to contribute to

the cell theory.

Anton van Leeuwenhoek Robert Hooke

1674 - Observed tiny living organisms in drops of pond water using a microscope

1665 - First to see plant tissue looking at cork through a microscope

3. Describe what these 3 scientists contributed to the cell theory.

Matthias Schleiden Theodor Schwann Rudolph Virchow

1838 Concluded that all plants are made of cells

1839 Concluded that all animals are made of cells

1855 Concluded that all cells come from existing cells

4. Biologists divide cells into two categories known as Prokaryotes and Eukaryotes. Compare the two types of cells with a Venn Diagram

1674

-Cell

membrane

-Cytoplasm

-DNA

-Grow

-Respond to

environment

-Reproduce

PROKARYOTE

-No Nucleus

-Free Floating DNA

-Unicellular

-Bacteria and

Eubacteria

EUKARYOTE

-Nucleus

-Organelles

-Some

unicellular

-Most

multicellular

-Plants,

Animals, Fungi,

Protists

Part B: Cell Organelles Structure and Function

1. Draw with COLOR and Label a plant and animal cell 2. Using information that can be found using your text (chapter 7), give the function

of the following organelles as well as the type of cell they are found in. 3. Place and X in the box if found in Plant, Animal and or Prokaryote

Structure Function Quick Picture

Animal Plant Prokaryote

1. Cytoplasm

Jellylike network of proteins that gives the cells shape. Sometimes involved with cell movement.

X X X

2. Cell Membrane

Regulates what enters and exits the cell, made of lipids, carbohydrates and proteins

X X X

3. Nucleus

Controls most of the cells functions and contains DNA

X X

4. Nucleolus

Nucleolus is the dense center containing the chromosomes.

X X

5. Ribosome

Small particles of RNA that produce proteins

X X X

6. Smooth Endoplasmic Reticulum

Contains enzymes for specific tasks (does not have ribosomes on the surface)

X X

7. Rough Endoplasmic Reticulum

This is where proteins are synthesized. (rough = ribosomes on the surface)

X X

8. Mitochondria

Cellular Respiration – uses energy from glucose to make ATP for growth and development

X X

9. Golgi apparatus

Location where proteins are “packaged” with other carbohydrates and lipids to be shipped out of the cell

X X

1. What organelles are found in plants cells that are NOT found in animal cells?

Cell wall, chloroplast, vacuole

2. Compare and contrast the following 2 organelles:

Mitochondria Chloroplast

Picture

Type of cell found in Plant and Animal Plant

Function in the cell Cellular Respiration Photosynthesis

Differences Makes energy ATP Contains chlorophyll Makes Glucose

Similarities Both have a inner and outer membrane

REACTANTS = PRODUCTS

Photosynthesis Equation:

CHOLORPLAST = PLANT CELLS

H2O + CO2 + Light = O2 + C6H12O6

Water + Carbon Dioxide + Light = Oxygen + Glucose

Cellular Respiration Equation:

MITOCHONDRIA = ANIMAL & PLANT

Cells

O2 + C6H12O6 = H2O + CO2 + ATP (Energy)

Oxygen + Glucose = Water + Carbon Dioxide + Energy (ATP)

10. Lysosome

Filled with enzymes to breakdown lipids carbs and proteins from food particles to be used

X X

12. Vacuole Store materials – usually water X

13. Centrioles Assist with cell replication = Mitosis

X

14. Chloroplasts

Photosynthesis - Uses energy from the sunlight to make the carbohydrate Glucose

X

15. Cell Wall

Gives structure to PLANT cells – made of cellulose

X

Part C: Levels of Organization Read pages 192 –193 of your book briefly describe and draw the following levels of organization.

Cells Tissues

Organs Organs Systems

TEST REVIEW 1. Study Vocabulary – Take Quizlet Vocabulary Quiz 2. Be sure ALL notes and diagrams are complete. 3. Complete Multiple Choice questions 1-10 on page 197 of text book.

4. Why is the cell membrane is called fluid mosaic?

The idea that the lipids, carbohydrates, proteins and cholesterol that make the cell membrane are constantly moving.

5. Draw and label a cell membrane? What are the functions of the 3 main parts?

6. What is osmosis? Give an example The movement of water. Example – when water moves out of your cells to dilute your blood after you eat salty foods.

7. What is diffusion? What are the 3 types of diffusion? Movement of molecules Simple, Facilitated and Active

8. How does osmosis and diffusion impact homeostasis of living organisms?

Osmosis and diffusion are always moving water and molecules towards equilibrium. This allows the organisms to maintain a relatively normal state and therefore maintain homeostasis.

9. How does passive and active transport differ?

Passive transport does not require energy while Active does require energy.

10. What helps passive and active transport occur across the cell membrane?

Passive and active transport both require protein channels to move molecules.

11. What is the difference between exocytosis and endocytosis? Is this active or passive? Exocytosis moves molecules out of the cell while endocytosis moves molecules into the cell. Both of these are active transport and require energy to occur.

12. How is a prokaryote cell different from a eukaryotic cell? How are they the same? Prokaryote Eukaryote

Same: -Cell membrane-Cytoplasm-DNA-Grow-Respond to environment-Reproduce

Different: -No Nucleus

-Free Floating DNA

-Unicellular

-Bacteria and Eubacteria

-Nucleus

-Organelles

-Some unicellular

-Most multicellular

-Plants, Animals, Fungi, Protists

13. What are the 3 statements of the cell theory?

A All living things are made of cells

B Cells are the basic unit of structure and function of all living organisms

C New cells are produced from existing cells

14. Who are the main scientists who contributed to this theory? What did they contribute? Anton van Leeuwenhoek Robert Hooke

1674 - Observed tiny living organisms in drops of pond water using a microscope

1665 - First to see plant tissue looking at cork through a microscope

Matthias Schleiden Theodor Schwann Rudolph Virchow

1838 Concluded that all plants are made of cells

1839 Concluded that all animals are made of cells

1855 Concluded that all cells come from existing cells

15. What is the function of the organelles?

Structure Function

5. Cytoplasm

Jellylike network of proteins that gives the cells shape. Sometimes involved with cell movement.

6. Cell Membrane

Regulates what enters and exits the cell, made of lipids, carbohydrates and proteins

7. Nucleus

Controls most of the cells functions and contains DNA

8. Nucleolus

Nucleolus is the dense center containing the chromosomes.

5. Ribosome

Small particles of RNA that produce proteins

6. Smooth Endoplasmic Reticulum

Contains enzymes for specific tasks (does not have ribosomes on the surface)

7. Rough Endoplasmic Reticulum

This is where proteins are synthesized. (rough = ribosomes on the surface)

8. Mitochondria

Cellular Respiration – uses energy from glucose to make ATP for growth and development

9. Golgi apparatus

Location where proteins are “packaged” with other carbohydrates and lipids to be shipped out of the cell

10. Lysosome

Filled with enzymes to breakdown lipids carbs and proteins from food particles to be used

12. Vacuole Store materials – usually water

13. Centrioles Assist with cell replication = Mitosis

14. Chloroplasts

Photosynthesis - Uses energy from the sunlight to make the carbohydrate Glucose

15. Cell Wall

Gives structure to PLANT cells – made of cellulose