Levels of Organization of Living Things

Big things are often made up of smaller parts

Different kinds of lliittttllee ppeeiicceess or units make up different parts of a

whole

Living things

are made up of cells

light microscope scanning electron microscope

Cells Tissues Organs Systems

Cell:Osteocyte

(student)

Tissue:Bone tissue

(class)

Organ:Bone

(grade)

Organ system:Skeletal system

(school)

Basic Functions of the Cell and Living Organisms

• Metabolism –Respiration–Nutrition–Digestion–Excretion

• Circulation• Growth• Reproduction

Metabolism:Respiration

Cells need oxygen and energy

Cells take oxygen (O2) from their surrounding

Cells also take glucose (C6H12O6) from their surrounding

Cells release carbon dioxyde (CO2) into their surrounding and

ENERGY

This process is called RespirationO2 + C6H12O6 CO2 + H2O + energy

Because of cellular respiration,

living organisms give off waste products through a process called excretion.excretion.

O2

C6H12O6

CO2

Because each and every cell in an organism depends on respiration and

excretion,

That organism must have some sort of circulationcirculation system in place to bring

each cell what it needs, and carry away its waste products

DeliveryDelivery PickupPickup

foot cells

O2CO2

nutrients

Interconnected systems

When an organism is at rest, it needs less energy.

Therefore its metabolism, (respiration and excretionexcretion) and

circulation are slow.

When an organism is at work, it needs more energy.

Therefore its metabolism,

(respiration and excretionexcretion) and circulation are fast.

In the same way that different sytems in the body perform different functions…

…different parts of the cell, called organelles,

perform different functions.

Organism Cells Tissues Organs Systems

System

Organ

Tissue

Cell

Organelles

Molecules

Atoms

(basic unit of life)

(parts of the cell)(parts of the cell)

The Basic Unit of Life: The Cell

Antony van Leeuwenhoe

k (1632-1723)

Robert Hooke(1635-1703)

chloroplastnucleus

mitochondriaendoplasmic

reticulumvacuolevacuolecell wall

MORE MORE POWERPOWER

                                        

                      

Plasma MembranePlasma Membrane

• keeps the contents of the cell (nucleus and cytoplasm) together

• The pores control the movement of atoms, molecules (O2,CO2 ) and simple sugars (food) accross the m

Nucleus

• Control center of the cell

• Contains DNA

• DNA contains all the information for cells to– perform their functions– reproduce

Cytoplasm

• Mostly water

• contents of a cell

- the nucleus.

Endoplasmic Reticulum

(ER) • Looks rough

when ribosomes are attached to it

• Site of protein synthesis

Golgi apparatus

• sorts and correctly ships the proteins

• certain cellular functions may stop if it is out of order (Cystic Fibrosis)

Mitochondria

• site of cellular respiration

• O2 + C6H12O6 CO2 + H2O + energy

• Number of mitochondria in cells depends on the cell’s usual energy requirements

VesiclesVesicles

• means "small vessel

• helps – store – transport

products produced by the cell

LysosomesLysosomes• contain enzymes that

cause the digestion of proteins

• pick up – harmful foreign invaders

(bacteria)– unwanted substances (old

food) – worn-out organelles

• break them into smaller pieces that are either– Recycled– Expelled from the c

Cytoskeleton

• Provides structure

• Microtubules are hollow tubes– Enable c

movement

• Actin filaments are thinner – Enable cellular

contractionIn a dividing cell

The Plant Cell

In addition to all the organelles of the animal cell, plant cells have

•a a cell wallcell wall•a vacuolea vacuole•chloroplasts

Cell WallCell Wall• Provides protection

and support for plants

• Materials cannot get through

• Plasmodesmata allow

• the transport of materials accross cell wall

• cell to cell communication

VacuoleVacuole

• Usually in the center of plant cells

• Stores large amounts of

– Water– sugars (molecules),

ions (atoms)Molecules Atoms

Chloroplasts

• Contain green pigments called chlorophylls which trap light energy from the sun

• Site of photo-synthesis

• Convert light energy of the sun into chemical energy packaged in sugar molecules

endoplasmic reticulum

mitochondrianucleusvacuolevacuole

chloroplastscell wall