Cell Type, Structure, & Function

 Bio.4 - Biology Science concepts. The student knows that cells are the basic structures of all living

things with specialized parts that perform specific functions and that

viruses are different from cells

What are the characteristics of life?

Characteristics of life:• Made of cells

• Use energy - metabolism

• Reproduce

• Respond to stimulus

• Change over time - grow

• Movement of materials

How do we define life?

Cell Theory • All living organisms are composed of cells

• Cells are the smallest structures that perform the functions of life

• All cells come from preexisting cells

Theory• Statements that explain a phenomenon;

repeatedly tested, widely accepted, and used to make predictions.

What do all cells have in common?

All cells have common structuresCell membraneRibosomeCytoplasm

Cells contain DNA

Cells are basic unit of life

Make a three column chart.

(Title of slide) Prokaryotes

Eukaryotes

Two types of cells Prokaryotes• •

Eukaryotes• •

Cell History

Cell size

Two Cell TypesProkaryotic•“pro” – BEFORE•“karyo” – kernel, nucleus•a cell type BEFORE the evolution of a nucleus

Eukaryotic•“eu” – true•“karyo” – nucleus•cell with a true nucleus

Cell History

Prokaryotic

Ancient cells

Evolved 3.5 bya

Billion years ago

Eukaryotic

Modern cells

Evolved 1.4 bya

Stromatolites, ancient bacterial formations

Cell SizeProkaryotic

Smaller cells

1 to 10 µm

Micrometer – 1/1000 of a meter

Eukaryotic

Larger cells

10 to 100 µm

Cell Size Comparison

Cell OrganizationProkaryotic

Simple cells with all parts in “one room”

Eukaryotic

Complex cells with many compartments

Location of DNAProkaryotic

DNA is loose in the cytoplasm,called a nucleiod

Eukaryotic

DNA is protected in the nucleus

Presence of OrganellesProkaryotic

Ribosomes

Cell membrane only

Eukaryotic

Many, membrane -bound organelles

Cell Structures and Functions

Animal Cell

Type of OrganismsProkaryotic

Bacteria only!

Eukaryotic

Plants, Animals, Fungi, and Protistsround Rod

shaped

Spiral shaped

Prokaryotes: Bacteria

Size of Organisms

ProkaryoticAlways unicellular

uni = one

SUPER SMALLEukaryotic

Mostly multicellular (more than one cell)

Range from cell size (microscopic) to the size of a sequoia tree (83 m=272 ft)

Cell ReproductionProkaryotes Eukaryotes

Viruses• Viruses are not

considered living because:

i. they are not made of cells and

ii. need a host cell to reproduce

• Viruses are much smaller than cells

• Viruses and cells both contain GENETIC MATERIAL

Capsid

Capsid – protein shell that protects genetic information of virus

What are the functions of the viral structures?

Genetic information – strands of DNA or RNA used to make viral proteins inside infected host cell

What are the functions of the viral structures?

Tail – protein shaft that contracts to inject viral genetic information into host cell

Viral Structure - Bacteriophage

Tail fibers – proteins that attach to the outside of a host cell

Viral Structure - Bacteriophage

Membranous envelope – lipids that attach and fuse to host cells membrane

Viral Structure – Other Types

Viruses• DNA or RNA as

genetic information

• Need a host to replicate

• Never contain organelles

• Do not convert energy

(metabolize)

Cellular Life• Only DNA as

genetic information

• Can reproduce independently

• Eukaryotes contain organelles

• Convert energy to perform tasks

Viruses vs. Cellular Life

• Viruses need a host to reproduce– Goal: create more copies of their genetic material

• Two methods– Lytic Cycle– Lysogenic Cycle

How do viruses reproduce?

• Lytic Cycle– Attaches to host– Injects genetic material into host– Cellular machinery duplicates genetic material and creates

viral proteins (capsids, tail fibers)– New viruses are assembled– New viruses exit the cell by bursting the cellular membrane

• End result – more viruses made, cell dies

Viral Reproduction – Lytic Cycle

Lytic Cycle Attachment

Entry

ReplicationAssembly

Release

Viral Reproduction – Lytic Cycle

• Lysogenic Cycle– Attaches to host– Injects genetic material into host– Viral genetic material is inserted into host genome– Viral genetic material lies dormant– When cell reproduces, new copies have viral genetic

information– Environmental stimulus sends viral DNA into lytic cycle

• End result – more viral genome made, cell lives

Viral Reproduction – Lysogenic Cycle

Lysogenic CycleAttachment

Entry

ReproductionInsertion

Separation

Viral Reproduction – Lysogenic Cycle

Lytic Cycle• New viruses

made• Cellular host dies

Lysogenic Cycle• Genome copies

made• Cellular host lives

Viral Reproduction

Lysogenic Cycle:– Herpes– HPV– Chicken Pox (can

become shingles)– HIV– Hepatitis B

Lytic:– SARS– Common Cold– Influenza– Rabies– AIDS phase of HIV– Tobacco Mosaic

Virus (in plants)

Common Viral Infections

Lytic & Lysogenic Cycles

Viral Reproduction

Cell Type, Structure, & Function

 Bio.4 - Biology Science concepts. The student knows that cells are the basic structures of all living

things with specialized parts that perform specific functions and that

viruses are different from cells

Cells Make Proteins

Structure & Function

What is structure?

A structure is a physical part, or a description of how something is built.

What is function?

A function is a job, a purpose, or a process that needs to be done.

What are organelles?

An organelle is a “mini organ” inside a eukaryotic cell that

carries out a specific function.

Cell MembraneLipid bilayer that surrounds the cell

Embedded proteins control what materials enter and leave the cell.

CytoplasmJelly-like fluid inside the cell

membrane

Supports and holds all the organelles

RibosomesWhere proteins are

assembled

Translate genes into proteins

Cell WallSupport, strength, and protection

Found outside plasma membrane;

made out of cellulose

Plant Cell Wall

Bacteria Cell Wall

Flagella/CiliaExtensions of the plasma

membrane that allow for movement

Bacteria with many flagella

NucleusMembrane bound area where

chromosomes are found

Holds the DNA, or genetic information

NucleolusDense region found in the nucleus where ribosomal RNA is made

ChloroplastsContains chlorophyll

Site of photosynthesis reactions

6H2O + 6CO2 C6H12O6 + 6O2

sunlight

MitochondriaProduces ATP (energy) for the cell

during cellular respiration

C6H12O6 + 6O2 6H2O + 6CO2 + ATP

Composed of inner and outer membrane

Endoplasmic ReticulumMembranous stacks with rough and

smooth sections

Participates in protein synthesis and membrane synthesis

Golgi Apparatus

Modifies and packages proteins for secretion by budding of vesicles

LysosomesContains enzymes that break

down cell wastes and foods

Recycle old cell parts

Lysosomes contain digestive enzymes

VacuoleStores water and pigments in plant cells

CentriolesUsed to organize chromosomes during cell

division using spindle fibers.

Cells Make Proteins

Cell Type, Structure, & Function

 Bio.4 - Biology Science concepts. The student knows that cells are the basic structures of all living

things with specialized parts that perform specific functions and that

viruses are different from cells