CELL STRUCTURE

AND FUNCTIONChapter 4 Notes

ROBERT HOOKE

First to observe cells 1665 Tree, Roots, Stems, Ferns, Cork “Tiny Boxes”

ANTON VAN LEEUWENHOEK

First to observe living cells 1673 Spirogyra & Vorticella

HOW BIG ARE THEY?

Utah.edu Site

CELL THEORY All living organisms are composed of

one or more cells. Cells are the basic unit of structure and

function in an organism. Cells come only from the reproduction of

existing cells.

CELL SHAPE

BASIC PARTS OF THE CELL Plasma membrane

Acts as a barrier – Materials enter and exit through the membrane

BASIC PARTS OF THE CELL

Inside

Outside

BASIC PARTS OF A CELL Plasma Membrane

AKA: Phospholipid Bilayer

Hydrophobic / Hydrophilic

Proteins

Carbohydrates

Markers

Channels

Receptors

FLUID MOSAIC MODEL

BASIC PARTS OF THE CELL Cytoplasm

-Region inside theMembrane

Cytosol – the liquid and cytoskeleton

BASIC PARTS OF THE CELL Control Center

Nucleus/Nucleiod

TYPES OF CELLS Prokaryote Lacks nucleus – Still has DNA Includes Bacteria and Achaea Kingdoms No membrane bound organelles Simple, Smaller

Eukaryote True nucleus – DNA bound by 2 membranes Includes Plant, Animal and Fungi Kingdoms Membrane bound organelles Complex, Larger

TYPES OF CELLS Prokaryote Lacks nucleus – Still has DNA Includes Bacteria and Achaea Kingdoms No membrane bound organelles Simple, Smaller

Eukaryote True nucleus – DNA bound by 2 membranes Includes Plant, Animal and Fungi Kingdoms Membrane bound organelles Complex, Larger

TYPES OF CELLS

BACTERI

A

TYPES OF CELLS

PLANT

S

ANIMALS

PROTISTS

FUNGI

CELL SIZE Size is limited by surface area-to-volume ratio As a cell grows, its volume increases faster than its surface area.

BACTERIA AND VIRUSES ARE SMALL AND SIMPLE How do you get big, and therefore open

up the possibility of becoming more complex and capable of doing more?

CELL SIZE

Surface Area = 1m X 1m X 6 sides = 6 m2 Surface Area = .5m X .5m X 6 sides X 8 cubes = 12 m2

Volume = 1m X 1m X 1 sides = 1m3 Volume = 1m X 1m X 1m = 1 m3

CELLULAR ORGANIZATION Colonial Organism vs. True Multicellularity

CELLULAR ORGANIZATION Colonial Organism vs. True Multicellularity Colonial: Organisms that live in a colony live in a

connected group but few activities are coordinated.

CELLULAR ORGANIZATION Colonial Organism vs. True Multicellularity Colonial: Organisms that live in a colony live in a connected group but few activities are

coordinated.

True Multicellular organisms have organization detailed below: Cell – Tissue – Organ – Organ System

Tissue = Group of cells that similar cells that carry out a specific function

Organ = Groups of tissue that perform a specific job Organ Systems = Groups of organs that accomplish related

tasks

CELLULAR ORGANIZATION

The smallest unit of life

CELLULAR ORGANIZATION

Some animals don’t even have

organs

CELLULAR ORGANIZATION

Bacteria & Viruses

A QUICK DETOURCHAPTER 23 & 24

A BIT OF CONFUSION…The things that make us ill..

A BIT OF CONFUSION…The things that make us ill could

be be…

BACTERIA ARE PROKARYOTES

Single celled organisms that do not have a membrane bound

nucleus

BACTERIAL ANATOMY

BACTERIAL REPRODUCTION & RECOMBINATION

Binary Fission

BACTERIAL REPRODUCTION & RECOMBINATION

Transformation

BACTERIAL REPRODUCTION & RECOMBINATION

Transduction

BACTERIAL REPRODUCTION & RECOMBINATION

Conjugation

NUTRITION & HABITAT

Obligate AnaerobeFacultative Anaerobe

Obligate Aerobe

HeterotrophAutotroph

“Photo” means uses light energy“Chemo” means extract energy from inorganic compounds

Must live O2 free

Can do with or without O2

Must have O2

Obligate Anaerobe

Facultative Anaerobe

Obligate Aerobe

2

1

3

IDENTIFYING BACTERIA

Shape/Growth Pattern

IDENTIFYING BACTERIA

Shape/Growth Pattern

IDENTIFYING BACTERIA

Gram Staining:Gram + have a petidoglycan rich cell wallGram – bacteria have a complex cell wall

Gram +

Gram –

RECALL…

The characteristics of living things:Organization

Response to StimuliHomeostasisMetabolism

Growth and DevelopmentReproduction

Change through time (evolve)

VIRUSES ARE NOT LIVING

They do NOT have cytoplasm or organelles and do NOT carry out metabolism or homeostasisThey DO have genetic information and DO reproduce (they just require a host cell to do so)

VIRUS ANATOMY

Nucleic Acid

Nucleic Acid

VIRUS ANATOMY

VIRAL REPLICATION

INFECTION!

INFECTION!

INFECTION!

Source:

-Influenza Virus

- Spread by direct transmission (when an infected person sneezes mucus directly into the eyes, nose or mouth of another person); airborne route (when someone inhales the aerosols produced by an infected person coughing, sneezing or spitting) and through hand-to-eye, hand-to-nose, or hand-to-mouth transmission, either from contaminated surfaces or from direct personal contact such as a hand-shake.

“The Flu”

INFECTION!

Source:

-Rhinovirus

-most common type of virus

INFECTION!

Source:

-Herpes Simplex Virus

-Transmitted by contact

(of infected area)

Symptoms:-Visible sores -Some infections can be permanent, with occasional outbreaks for life

INFECTION!

Source:

-Herpes Simplex Virus

-Transmitted by contact

(of infected area)

Symptoms:-Visible sores -Some infections can be permanent, with occasional outbreaks for life

INFECTION!

Source:

-B. Anthracis/Spores

- Symptoms:-Visible sores -Can infect skin, Gastrointestinal tract And respiratory tract

INFECTION!

Source:

-B. Anthracis/Spores

- Symptoms:-Visible sores -Can infect skin, Gastrointestinal tract And respiratory tract

INFECTION!

Source:

-Ebola VirusSymptoms:

-Fever, chills , vomiting(flu-like symptoms)

-Agitation, confusion

-Edema

-Hemorrhagic fever

INFECTION!

Source:

-HIV Virus

INFECTION!

Source:

-Salmnella or E.Coli in undercooked/contaminated food

“Food Poisoning”

Symptoms:

-Fever, chills , diarrhea, vomiting(flu-like symptoms)

INFECTION!

INFECTION!

Source:

-often caused by one of group b streptococcus

Symptoms:

-Flu like symptoms followed by serious issues related to swelling in the brain

INFECTION!

Source:

-Streptococcus pyogenes

(a group a streptococcus)

Symptoms:

-Flesh eating bacteria

INFECTION!

Source:

- Staphylococcus Aureus

Symptoms:

-Sores

INFECTION!

Source:

- Staphylococcus Aureus

Symptoms:

-Sores

INFECTION!

Source:

- Neisseria gonorrhoeae

Symptoms:

-Wart like sores that ooze puss

OK, BACK TO THE COMPLEX CELLS THAT CAN BUILD MULTICELLULAR ORGANISMS.

CELL ORGANELLES Nucleus DNA is like a reference book. It DOES NOT

leave the nucleus

DNA controls PROTEIN SYNTHESIS

therefore controls the cell

Nuclear Envelope – 2 Layers

Nuclear Pores

Nucleolus

DNA – Chromatin - Chromosomes

CELL ORGANELLES MitochondriaTransfer energy from organic molecules

to ATP

Site of CELLULAR RESPIRATION

Mitochondrial DNA

You’ve got lots of these….they make energy!

CELL ORGANELLES Ribosomes

Smallest, most numerous organelle

Free floating, in Nucleus, on E.R.

Site of PROTEIN SYNTHESIS

You’ve got lots of these…they make protein!

CELL ORGANELLES Endoplasmic Reticulum

Cistern

Rough – Has ribosomes on it

Smooth – No ribosomes

Vesicles pinch off for exporting materials.

E.R. CONTINUED… Rough ER– Produces phospholipidsand proteins. These products are later used or exported.

EX: digestive enzymes Smooth ER – Produces lipids like Steroids (testosterone, estrogen) and Cholesterol. Helps detoxify drugs and poisons.

CELL ORGANELLES Golgi ApparatusReceive and modify products of the E.R.

Package for export out of cell

Can label or add carbs to proteins

or alter lipids

CELL ORGANELLES Vesicles

Lysosomes Bud off of GA – Contain digestive enzymes Autophagy – Digestion of worn out organelles

Peroxisomes Abundant in liver and kidney cells Neutralize free radicals H2O2 – Produced when breaking down alcohol

and killing bacteriaOther Vesicles

Endosome (from engulfing something) Glyoxysomes (break down stored energy in plant

seeds)

CYTOSKELETON Microtubules

Hollow tubes of tubulin (a protein) that radiate from the centrosome

Help maintain shape of cell, aid in organelle movement (act as tracks)

CYTOSKELETON Microfilaments

Long threads of actin (a protein)Contraction leads to cell movement

CYTOSKELETON Intermediate Filaments

Rods that anchor the nucleus and some other organelles in their place

Maintain cell and nucleus shape

CYTOSKELETON Cilia and Flagella

Hair like structures that extend from cell surface Cilia – Short and numerous Flagella – Much longer (not as many) They have a membrane on the outer surface and nine pairs of

microtubules around two central tubules.

CYTOSKELETON Centrioles

Two short microtubule cylinders Organize microtubules and cytoskeleton

during cell division in animal cells

CYTOSKELETON

COMPARING CELLS Animal Cell

eukaryoticmembrane bound organelles true nucleus

Plant

everything an animal cell has &…cell wall large central vacuoleplastids

PLANT CELLS Cell Wall

Rigid layer outside plasma membrane Contains cellulose (a carbohydrate)Some plants produce secondary cell walls

PLANT CELLS Central Vacuole

Large, fluid-filled organelle that stores water (and enzymes, waste and other materials)

Up to 90% of cells volume

PLANT CELLS Chloroplasts

Site of PhotosynthesisThylakoids (membrane sacs) contain

Chlorophyll (a pigment)Contain their own DNA

PLANT CELLS Chromoplasts

Contain colorful pigments that may or may not help photosynthesis

WHERE DID ORGANELLES COME FROM?

http://www.sumanasinc.com/webcontent/animations/content/organelles.html

A COOL VIDEO Inner Lifehttp://multimedia.mcb.harvard.edu/media.hml

HOW CAN WE OBSERVE CELLS? Microscopes!

Ocular Objective

Arm

Stage

Base

Stage Clips

Light Source

Nose Piece

Low Power Objective

Medium Power Objective

High Power Objective

Diaphragm

Coarse Adjustment

KnobFine Adjustment

Knob