UNIT 1- THE CELL

CELL THEORY

& FUNCTION

A Word From Bill

• Record your

observations about the

picture to the right.

• What do you think you

are you looking at?

• Describe the structure

with as much detail as

possible?

• Is there organization

to what you see?

• Is it a single unit or

many units?

• Can’t see cells, so who knew they existed?

• Discovered after the microscope was invented.

• Mid 1600s when scientists began using microscopes

• Robert Hooke – used a microscope to look at a thin slice of cork (a plant material).

• Cork = thousands of tiny, empty chambers.

• R.H. said chambers = “cells” because they reminded him of a monastery’s tiny rooms

DISCOVERY OF THE

CELL

Today we

know cells

aren’t empty

chambers….

They contain

living matter!

SCIENTISTS OF CELL THEORY

Robert Hooke-First to observe cells. (1665)

Anton van Leeuwenhoek- first to observe living cells.(1674)

Matthias Schleiden- first to state plants are made of cells. (1838)

Theodore Schwann-animal tissues are made of cells. (1839)

Numerous observations made it clear that

cells were the basic unit of life.

THE CELL THEORY

1. All living things are composed of cells.

2. Cells = basic units of structure and

function in living things.

3. New cells R from existing cells.

CELL THEORY

Researchers use microscopes and techniques more powerful than

before!

i.e. Fluorescent labels and light microscopy to follow molecules

moving through the cell.

Confocal light microscopy, which scans cells with a laser beam,

makes it possible to build three-dimensional images of cells and

their parts.

High-resolution video technology makes it easy to produce

movies of cells as they grow, divide, and develop.

NOWADAYS…

CELL SIZE LIMITS

Cells need to be small for the purposes of diffusion of

materials into and out of the cell across the cell membrane.

The cell membrane surface area-to-volume ratio limits how

large a cell can be in order be able to perform metabolic

functions.

As a cell gets larger the volume of the cell increases at a faster

rate then the radius.

If the cells radius increase 10 times the volume will increase by

100 times

CELL SHAPE

A cells shape reflects the different functions of cells.

Each cell shape has evolved to allow the cell to effectively

perform its job.

A nerve cells has long extensions that reach out in various

directions for sending and receiving nerve impulses

A Skin cell is a flat , platelike cells that protect the surface of

the body.

• Smaller & simpler than eukaryotic cells (exceptions to this

rule).

• Prokaryotic cells have genetic material ≠ contained in a

nucleus.

• Prokaryotes carry out every activity associated with living

things. (grow, reproduce, respond to the environment, some

can move by swimming through liquids!)

Bacteria are prokaryotes!

PROKARYOTES

• Larger and more complex.

• Generally contain dozens of structures and internal

membranes, and many are highly specialized.

• Eukaryotic cells contain a nucleus = genetic material is

separated from the rest of the cell.

• Some eukaryotes = unicellular organisms.

• Others form large, multicellular organisms (plants, animals,

fungi, protists).

EUKARYOTES

PROKARYOTE VS EUKARYOTE

7-2 Eukaryotic Cell Structure p.

174

1. nucleus

2. nucleolus

3. nuclear membrane (envelope)

4. cytoplasm

5. chromosomes

6. cell membrane

7. endoplasmic reticulum (rough)

8. ribosome

9. Golgi apparatus (body)

10. mitochondria

11. lysosome

12. chloroplast

13. cell wall

14.Vacuole

15 endoplasmic reticulum

(smooth)

16. centrioles

EUKARYOTES

ORGANELLE REVIEW GAME

Review: What is the difference between

a eukaryote and a prokaryote?

Q/A

CELL ORGANELLES

An organelle (tiny organ)- is well-defined, intracellular body

that performs specific functions for the cell.

CYTOPLASM

The cytoplasm is the region of the cell inside of the cell

membrane.

It includes: fluid, the cytoskeleton and all organelles except the

nucleus.

CELLULAR ORGANIZATION

Unicellular-One celled organism

Multicellular-many celled organism

Over time cells began to form groups that functioned

together to create multicellular organism.

TYPE OF UNICELLULAR

MOVEMENT

Cilia-tiny little hair like structures.

Flagella- Whip-like tail.

Psuedopodia- “false foot” extension of the cytoplasm.

BELL RINGER

Where does most energy come from? How do

you get energy?

What processes are involved with you obtaining

energy. (list as many as possible)

OVERVIEW

All living things need energy to survive.

Almost all of the energy used by organisms comes from the

sun.

Organisms that can use the sun to create food are called

autotrophs.

Auto-self Troph-feeding

Examples include: algae, plants, some protists and some

prokaryotes.

Even organisms that are not autotrophs rely on autotrophs for

energy either directly (herbivores) or indirectly (higher level

consumers).

Heterotrophs- must get energy from the food they eat.

PHOTOSYNTHESIS

Photosynthesis is a series of complex chemical

reactions that converts light energy from the sun

into chemical energy in the form of organic

compounds (i.e. carbohydrates).

PHOTOSYNTHESIS

The molecules used (reactants) during

photosynthesis include:

Carbon Dioxide (CO2) , Water (H2O)

The molecules created (products) include:

Glucose (C6H12O6), Oxygen O2

Chloroplast pg. 208

6 CO2 + 6 H2O + energy carbon dioxide water sun

C6H12O6 + 6 O2glucose oxygen

Photosynthesis

FACTORS THAT AFFECT

PHOTOSYNTHESIS

Typical Plant Cell

Video

CELLULAR RESPIRATION

CELLULAR RESPIRATION

When you eat food you get energy from breaking

that food down into simpler molecules.

Cellular Respiration-a complex process in which

cells make ATP (adenosine triphosphate) by

breaking down organic compounds.

BOTH autotrophs (plants) and heterotrophs use

Cellular Respiration.

CELLULAR RESPIRATION

The products of cellular respiration are the reactant of photosynthesis.

Cellular Respiration is divided into 3 stages.

Glycolysis

Aerobic Respiration (with oxygen)-Krebs cycle

Electron Transport Chain

The main focus is to get ATP (adenosine triphosphate) the universal energy molecule. It is like money.

ATP

ATP is the universal energy

currency in the cell. It has 3

phosphate groups attached.

It is high energy molecule.

When it releases a phosphate

group it releases energy and it

becomes ADP (adenosine

diphosphate).

WHERE DOES CELLULAR RESPIRATION OCCUR?

It occurs in the cytoplasm (glycolysis)

and the mitochondria.

Video

How is it possible for the plant and

the fish to survive in this closed

ecosystem where oxygen can not

enter or escape?

Why would an enclosed ecosystem

based on land be harder (not

impossible) to create?

QUESTION FOR

UNDERSTANDING

Typical Animal Cell

Why do plant cells need BOTH

chloroplasts and mitochondrion?

Why do animal cells only have

mitochondrion?

QUESTION

Understanding how mitochondrion

work, what cell would you expect to

have more mitochondrion present in

a bird:

An eye cell

A muscle wing cell

A foot cell

?

QUESTION

CELLULAR RESPIRATION VS PHOTOSYNTHESIS FOLDABLE

1-Mitochondria and Chloroplasts-

For marks (homework)

2-Concept: Photosynthesis and

Respiration- For marks (homework)

3-Thinking critically about

photosynthesis: in class, review in

class, good source for short answer

questions on a test

4-`The Chloroplast- for notes,

answers will be on the website

BELL RINGERS

CELL QUIZ

1. Contains digestive enzymes.

2. Control center.

3. Provides structure in a plant cell.

4. Contains chlorophyll.

5. Carbohydrate producers.

6. Stores, modifies, transports materials.

7. Storage organelle.

8. Pathway through cell.

9. Tiny internal support structure.

10. Power house.

11. Allows certain things in and out of a cell.

12. Many of these in muscle cells.

13. These cells are special because they do not have a nucleus.

14. Make ribosomes.

15. Involved in cell reproduction.

16. These cells are special because they have DNA in a nucleus.

BELL RINGERS

7.2 (pg. 174-181)