The World of Cells

The Cell

What is a cell?

● The basic unit of structure and function of all

living things.

● The basic building block of all organisms.

What are organelles?

● Humans have organs

● Cells contain

organelles

● These organelles are

like tiny organs inside
a cell.

● For example: A

nucleus acts like the
brain of the cell.

Nucleus

History

● Robert Hooke – first

to discover cells.

● Looking at Cork under

the microscope.

History

● Schleiden

● Botanist who said all

plants are made of
cells.

History

● Schwann

● Zoologist who said all

animals are made of
cells

History

● Virchow

● All living cells come

only from other living
cells.

Cell Theory

● All living things are made up of cells

● Cells are the basic units of structure and function of

living things

● Living cells come only from other living cells.

What’s the difference anyway?

● Theory

● Tested and based on results,

develop an idea that could
explain the problem.

● Can be proven true or false

by others

● Theory of Evolution, the BIG

Bang Theory

● Law

● Doesn’t need to be

tested, because we
KNOW it to be true

● Each time, it has the

same outcome

● The law of gravity

Organization of an organism

Basic Structures of a cell

● All cells share certain

structures that make them
a cell

● All cells must contain at

least 4 basic structures to
be considered a living cell
● Cell membrane
● Ribosomes

-- DNA
● Cytoplasm

The Cell

Cell Membrane:

2. Separates the cell from the
outside environment

3. The membrane is what makes
a cell… a cell.

1. ALL CELLS

The Cell

Ribosomes:

3. Proteins are made here
from DNA instructions to
carry out the functions of life

1. ALL CELLS

2. Found in the

cytoplasm & on E.R.

The Cell

Cytoplasm:

2. The ENVIRONMENT of the

cell. All organelles float in it

1. ALL CELLS

TWO TYPES OF CELLS

● PROKARYOTES – DO NOT contain a NUCLEUS or

membrane bound organelles

Ex: bacteria

● EUKARYOTES – DO CONTAIN A NUCLEUS and

contain membrane bound organelles.

● Ex: animal and plant cells

The Cell

Nucleus:

3.

Control Center

of the cell

1. Animal & Plant Cells

2. Center of the cell

The Cell

Cell Membrane:

2. Controls the movement of

material into & out of the cell

3. Selectively Permeable – chooses
what enters and exits the cell

1. Animal & Plant Cells

Cell transport - Diffusion

● Diffusion

● the process by which

molecules spread from
areas of high
concentration, to areas
of low concentration

● Does not require Energy;

happens naturally

● Passive Transport****

● Equilibrium

● when the molecules are

even throughout a space

Passive Transport: No energy

Concentration Gradient - change in the concentration of a

substance from one area to another.

Active Transport

● Requires Energy

● Low to high concentration

Osmosis
● 75 % of cells is water

● the diffusion of water (across a

membrane)

● Water will move in the

direction towards where there
is a high concentration of
solute (and hence a lower
concentration of water)

● Does not require Energy;

happens naturally

Endo = In

Exo = Out

Sections of the membrane “swallow” substances

and bring them into or out of the cell

Endocytosis and Exocytosis

Review: Producers

● Producers get their

energy from the sun.

● Producers convert this

light energy into
stored chemical
energy (glucose).

● This process is called

photosynthesis.

Review: Consumers

● Consumers get their

energy from the
producers.

● Consumers convert

stored chemical
energy (glucose) into
usablechemical
energy (ATP).

● This process is called

cellular respiration.

Cellular Respiration (aerobic)

▪ Cellular respiration is the process by which glucose

(C6H12O6) is broken down to release energy for making
ATP, another form of chemical energy.

Aerobic Respiration –

Equation

C6H12O6 + 6 O2 6 H2O + 6 CO2 + 36 ATP

food
(glucose, a carbohydrate)

oxygen

water

carbon
dioxide

Chemical Equations

Photosynthesis:

6 H2O + 6 CO2 + energy (sun) → C6H12O6 + 6 O2

Aerobic Cellular Respiration:

C6H12O6 + 6 O2 → 6 H2O + 6 CO2 + energy (ATP)

Why ATP? An analogy to

money…

● Glucose in our food is a great source of energy! ($100 bill)

● However, individual cell processes may only require a small

amount of energy ($1 bill)

● Analogy: most vending machines do not accept $100 bills!

We need a smaller form of “currency” for these processes.

● ATP (adenosine triphosphate) is this important cellular

“currency” for life.

● ATP releases more appropriate amounts of energy for the

individual cellular processes that require energy.

The BIG Question is…

Do only animals respire?

Or do plants respire too?

● Only plants perform photosynthesis

● Plants AND animals perform cellular respiration!

(Can you explain why??)

Site of Cellular Respiration

● Plant and animal cells contain mitochondria: cell

structures that transform chemical energy from
glucose to ATP.

Significant ATP Production

● Aerobic cellular respiration releases energy SLOWLY, using

oxygen to convert ONE molecule of glucose to 36 ATP!

Cellular Metabolism & Energy

● Cellular Respiration

● Process where organisms use

food to make usable energy
for cells

● Step 1: Glucose is broken

down in the cytoplasm

● Step 2: Oxygen helps

Energy captured to be
changed into ATP for
cellular use in the
mitochondria

The CellMitochondria:

3. Makes ENERGY for the cell.

1. Animal & Plant Cells

2. RESPIRATION occurs here
(use of oxygen to break down
food particles for energy)

2 types of Cellular Respiration

● Aerobic Respiration

● Requires Food & Oxygen

● Water and CO2 are waste

products

● Food + Oxygen

CO2 + Water + ATP

● Energy not used is stored as

fat

2 Types of Cellular Respiration

● Anaerobic respiration is also called

fermentation, or the process by
which energy is released from
glucose when oxygen is NOT
available.

● This process allows organisms to

continue to produce energy until
oxygen is available.

● However, this process only

releases 2 ATP per molecule of
glucose.

The Cell

Vacuoles:

3.

FOOD, WATER, and

Waste are STORED here

1. In Plants (LARGE) &
Animal
2. Floating in the cytoplasm

The Cell
Lysosomes:

3.

Digests food or Recycles
old or dead cell parts

1. Mostly Animal

2. Floating in the cytoplasm

Protein Synthesis

Protein Production
Process where organisms use the instructions in DNA to
make proteins for specific jobs in or outside the cell
Step 1: DNA is translated into a protein by the
ribosomes
Step 2: Proteins are processed and transported in the
ER and packaged in movable vacuoles called vessicles
and shipped to needed locations inside/outside the cell
by the golgi bodies.

The Cell

Ribosomes:

3.

Proteins are made here

Using instructions from DNA

1. Animal & Plant Cells

2. Found in the

cytoplasm & on E.R.

The Cell
Endoplasmic Reticulum
(E.R.):

3. Transports materials in the cell
(TRANSPORTATION SYSTEM)

1. Animal & Plant Cells

2. Found around the nucleus
and throughout the cytoplasm

The Cell
Golgi bodies:

3. Package & Ships cell materials

1. Animal & Plant Cells

2. Floating in Cytoplasm

Major differences between a

plant and animal cell

● Plant cells have a cell wall –

animal cells do not.

● Plant cells have chloroplasts

– animal cells do not

● Plant cells have a much

larger vacuole than animal
cells

● Animal cells have

lysosomes, plants do not

The Cell
Chloroplast:

3. Makes food for cell

(Photosynthesis – captures

ENERGY IN SUNLIGHT)

4. Contains CHLOROPHYLL

To absorb sunlight

1. Plant Cells

2. Floating in Cytoplasm

The Cell

Cell Wall:

3.

STRONG to provide

Structure and support

1. Plant Cells – NOT IN
ANIMALS!!
2. Gives plant cells its shape

Cellular Metabolism & Energy

● Photosynthesis

● Process where plants use

light for food

● Step 1: Energy in the form of

sunlight is captured by the
chlorophyll in the
chloroplast

● Step 2: Energy captured is

changed into food for plant

Photosynthesis

● Sunlight + CO2 +

Water

Glucose (food) + O2

REMEMBER – PLANTS

STILL COMPLETE

RESPIRATION!

10

9

2

3

4

5

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7

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1

Review:

•

Is this a plant or
animal cell?

•

Label the numbers

The Cell

1
2

3

4

5

6

7

8

Cytoplasm9

10

Nucleolus

Ticket at the door – 5 points

Number your paper from 1 – 5. Answer the questions.

1.What two organelles are unique to plant cells?

2.Does a prokaryotic cell have a nucleus? Yes or no

3.Does active transport require energy? Yes or no

4.What two things are needed to perform cellular
respiration?

5.Do all cells perform cellular respiration? Yes or no