Cell Organelles

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AP Biology 2011

By: Shane Macfarlane and Amy Halonen

•Has a nuclear membrane

•Contains chromatin r

•The nucleus contains genetic material (DNA)

•The liquid inside is called the nucleoplasm

Function

• The nucleus is found in eukaryotes

• Contains and replicates genetic material (DNA)

• Regulates cell activity

• Uses messenger RNA to help produce proteins

Analogy

• An analogy for the nucleus is the human brain because like the nucleus the brain controls the bodies action

• Also the nucleus contains DNA which is like the brains storage of memory.

The Ribosome - Structure

�Image 1 show the location of the ribosome in the cell.

�The ribosomes are either bound to the endoplasmic

reticulum (causing the ER to be rough) or, less often,

floating free in the cytosol.

�A ribosome is composed of two subunits: ribosomal

RNA and protein.

1

The Ribosome – Function

• Purpose of the ribosomes is to carry out protein synthesis.

• Cells that have high rates of protein synthesis have a large number of ribosomes (ex. The pancreas).

• Free ribosomes produce proteins that function within the cytosol (ex. The first steps of breaking down sugar).

• Bound ribosomes produce proteins that may be inserted into membranes, packaging with various organelles or secretion from the cell.

• The synthesis of the proteins depends on the mRNA from the nucleus.

Nucleus Ribosome = Coach Athlete

Endoplasmic Reticulum Endoplasmic Reticulum

(ER)(ER)

Maggie Hogan Maggie Hogan

&&

Amanda WrightAmanda Wright

StructureStructure�� Consists of a network of Consists of a network of

membranous tubules and membranous tubules and

sacs called cisternae. sacs called cisternae.

�� There are two regions: There are two regions:

--Smooth ERSmooth ER-- its its cytoplasmiccytoplasmic

surface lacks surface lacks ribosomesribosomes

--Rough ERRough ER-- the the cytoplasmiccytoplasmic

surface is studded with surface is studded with

ribosomesribosomes. .

FunctionFunction

�� Smooth ERSmooth ER-- Involved with diverse Involved with diverse

metabolic processes. metabolic processes.

Ex. Synthesis of lipids, metabolism of Ex. Synthesis of lipids, metabolism of

carbohydrates, detoxification of drugs and carbohydrates, detoxification of drugs and

poisons.poisons.

�� Rough ERRough ER-- Synthesizes Synthesizes secretorysecretory proteins proteins

and it produces membrane. and it produces membrane.

AnalogyAnalogy�� The endoplasmic reticulum is like a factory The endoplasmic reticulum is like a factory

making lipids and proteins. The walls of the making lipids and proteins. The walls of the

factory look like the walls of the endoplasmic factory look like the walls of the endoplasmic

reticulum. reticulum.

Golgi ApparatusGolgi Apparatus

By: Cam FrittsBy: Cam Fritts

JaymieJaymie DyerDyer

StructureStructure

�� Consists of flattened membranous sacs called Consists of flattened membranous sacs called

cisternaecisternae which are not physically connectedwhich are not physically connected

�� CisCis faceface--receives vesicles containing ER productsreceives vesicles containing ER products

�� Trans faceTrans face-- dispatches vesiclesdispatches vesicles

FunctionFunction

�� Manufacturing, warehousing, sorting, and Manufacturing, warehousing, sorting, and

shippingshipping

�� Products of the ER are modified, sorted, and Products of the ER are modified, sorted, and

sent to other destinationssent to other destinations

�� Engaged in the transfer of material between the Engaged in the transfer of material between the

Golgi and other structuresGolgi and other structures

�� Manufactures certain macromolecules by itselfManufactures certain macromolecules by itself

�� Refines its products in stages with different Refines its products in stages with different

cisternaecisternae

AnalogyAnalogy

�� An analogy to the Golgi Apparatus would An analogy to the Golgi Apparatus would

be a UPS shipping warehouse.be a UPS shipping warehouse.

�� The Golgi Apparatus modifies, stores and The Golgi Apparatus modifies, stores and

then ships vesicles to other destinationsthen ships vesicles to other destinations

�� The UPS shipping warehouse stores The UPS shipping warehouse stores

products and ships them out when products and ships them out when

requestedrequested

Lysosome and Lysosome and

PeroxisomePeroxisome

By Nicole Schnabel and By Nicole Schnabel and

Jessica PlastowJessica Plastow

Function in the CellFunction in the Cell

�� LysosomeLysosome

�� Uses a sac of hydrolytic Uses a sac of hydrolytic

enzymes to digest enzymes to digest

macromolecules.macromolecules.

�� Recycles the cellRecycles the cell’’s s

organic material.organic material.

�� In PhagocytosisIn Phagocytosis

�� Small organisms or food Small organisms or food

particles are engulfed. particles are engulfed.

�� Form a food vacuole that Form a food vacuole that

fuses with the lysosome, fuses with the lysosome,

�� Enzymes digest the food.Enzymes digest the food.

�� PeroxisomePeroxisome

�� A microbody that A microbody that

contains enzymes thatcontains enzymes that

�� Detoxifies harmful Detoxifies harmful

substancessubstances

�� Breaks down fatty acids.Breaks down fatty acids.

�� Transfers Hydrogen Transfers Hydrogen

from various substrates from various substrates

to oxygen.to oxygen.

�� Produces Hydrogen Produces Hydrogen

Peroxide which it then Peroxide which it then

breaks down.breaks down.

Structure of the LysosomeStructure of the Lysosome

�� A circular near the Nucleus that A circular near the Nucleus that

contains a sac of digestive enzymes.contains a sac of digestive enzymes.

Structure of the PeroxisomeStructure of the Peroxisome

�� Roughly sphericalRoughly spherical

�� Granular or crystalline Granular or crystalline

core that is a dense core that is a dense

collection of enzymes.collection of enzymes.

MetaphorsMetaphors

�� LysosomeLysosome

A Lysosome is the A Lysosome is the stomach of the cell. It stomach of the cell. It digests food particles. digests food particles.

�� PeroxisomePeroxisome

A Peroxisome is the A Peroxisome is the water treatment plant water treatment plant of the cell, because it of the cell, because it detoxifies the cell so it detoxifies the cell so it can continue to can continue to function. Just like function. Just like water is detoxified for water is detoxified for reuse.reuse.

The Structure of a Vacuole

• Vacuoles are membrane-bounded sacs within the cell. Food vacuoles are formed by phagocytosis. Vacuoles can be found in both animal and plant cells, but are usually much larger in plant cells. Most mature plant cells have a Central Vacuole. This is typically the largest compartment in a plant cell. The central vacuole is enclosed by a membrane called the tonoplast.

The Functions of a Vacuole

• Vacuoles can have different functions depending on the type of cell it is, but generally they function as storage for food and water, waste disposal, protection, and growth. Some vacuoles like contractile vacuoles, main function is to pump excess water out of the cell. While other vacuoles may store a pigment that color the cell, such as the pigments on a flower’s petals that help attract pollinating insects. Other Vacuoles can be filled with compounds that are poisonous to animals for protection.

The Analogy of a Vacuole

• Vacuoles in a cell are basically like the cells warehouse. They

store food, water, and other things for the cell.

By: Jen English and Marissa Shoemaker

Structure• About 1-10 mm long • The cristae give the inner mitochondrial membrane a

large surface area that enhances the productivity of cellular respiration, another example of structure fitting function.

• Enclosed by two membranes, each a phospholipidbilayer with a unique collection of embedded proteins – Outer membrane = smooth

– Inner membrane =Cristae• divides the mitochondrion into two internal

compartments

– 1) Intermembrane space, the narrow region between the inner and outer membranes

– 2) mitochondrial matrix, is enclosed by the inner membrane. The matrix contains many different enzymes as well as the mitochondrial

Function

• Used to provide energy to the cell

• “Power house” of the cell

• The sites of cellular respiration

• The sites of catabolic process that generates ATP by extracting energy from sugars, fats, and other fuels with the help of oxygen.

Analogy

• The mitochondria

is just like a

power plant. The

mitochondria

produces power

for the cell just

like a power plant

produces energy

for a city.

ChloroplastsChloroplasts

By By SavanahSavanah Moore and Jacqueline Bull Moore and Jacqueline Bull

44thth HourHour

StructureStructure

�� StromaStroma: Fluid outside of the : Fluid outside of the thylakoidsthylakoids. Contains DNA, . Contains DNA,

enzymes, and enzymes, and ribosomesribosomes

�� GranumGranum: Many : Many thylakoidsthylakoids stacked up.stacked up.

�� ThylakoidThylakoid: : MembraneousMembraneous system of flattened sacks. system of flattened sacks.

�� Inner and outer membranes: Separate the Inner and outer membranes: Separate the stromastroma and and

the the ThylakoidThylakoid space.space.

�� Plastids: Specialized plant organelles, like Chloroplast.Plastids: Specialized plant organelles, like Chloroplast.

�� Chlorophyll: Green pigment.Chlorophyll: Green pigment.

Structure Cont.Structure Cont.

FunctionFunction

�� Photosynthetic organelle; converts Photosynthetic organelle; converts

energy of sunlight to chemical energy energy of sunlight to chemical energy

stored in sugar molecules.stored in sugar molecules.

�� Chloroplasts move around cell like Chloroplasts move around cell like

mitochondria and other organelles.mitochondria and other organelles.

AnalogyAnalogy

�� Chloroplast is like a car engine. It Chloroplast is like a car engine. It

converts the raw substance (sunlight) converts the raw substance (sunlight)

into a new form of energy. Cars do the into a new form of energy. Cars do the

same thing by converting gas into kinetic same thing by converting gas into kinetic

energy.energy.

Cytoskeleton: MicrotubulesAdam Mossoian

Hayden Sowa

Structure

• Part of the three fibers that make up the cytoskeleton.

• They are found in the cytoplasm of all eukaryotic cells.

• Hollow rods that measure 200 nanometers by 25 micrometers in length.

• Wall of the tube is constructed from globular proteins called tubulin.

• Microtubules can be disassembled and their tubulin can

be used to build microtubules elsewhere in the cell.

• Centrioles are formed from nine sets of three

microtubules.

Function• Carry out the function of

retaining the cells shape.

• Centrioles are in the middle of all microtubules in the

cell.

• Centrioles aid in dividing the cell during mitosis.

• Transportation system for organelles with motor

molecules.

• Responsible for the

separation of chromosomes during cellular division.

Analogy

• Trunks are to branches as centriolesare to microtubules.

• When buildings are constructed a foundation is laid on the ground in

order for the support beams, which are

similar to microtubules in the sense that they keep the whole structure

together.

• Microtubules are to cytoskeleton as a

bone is to the skeletal system.

By Lucas and Katie

Intermediate Filaments-

-Consist of fibrous

proteins super coiled into

thick strands

-Proteins are made up of

several from the keratin

familyMicrofilaments-

-Consist of two intertwined strands of the protein actin

Micro-filaments

Maintain cell-shape

(through Tension)

Change cell shape

Muscle contraction

Cytoplasmic streaming

Cell motility (pseudopodia)

Cell division

Intermediate Filaments

Maintains cell-shape (through tension)

Anchorage of nucleus and

certain other organelles

Formation of nuclear lamina

Usually more permanent fixtures

in cell

AnalogyAnalogy

Microfilaments act as cables

attached to cranes that move by

contracting or extending objects

on a construction site

Intermediate filaments

Act as cables that support a

structure such as a radio tower

Cell Wall

By: Elizabeth Glasco, and Rachel Piper

Structure• Only in plant cells and some prokaryotic cells

• Thicker than the plasma membrane

• Ranges from .1micrometer to several micrometers

• Composition varies from species to species and from one cell to another

• Has microfibrils, made of polysaccharide cellulose, that are embedded in other polysaccharides and protein

• There is a thin, flexible layer, called the primary cell wall

• Inbetween the primary walls is a thin layer of sticky polysaccharides (pectins) called middle lamella

• Secondary cell wall is between the plasma membrane and the primary cell wall

• Primary forms when the cell is young, and the secondary wall comes later

Function

• The cell wall (mainly the secondary wall) protects plant cells and helps them to keep their shape

• It prevents excess uptake of water

• It holds the cell up against the force of gravity

AnalogyA cell wall is like a building. A

building keeps the shape of the

area people live or work in along

with protecting people from

weather.

Extracellular MatrixExtracellular Matrix

By: Derek By: Derek AndreenAndreen

Jessica Armstrong Jessica Armstrong

StructureStructure

It is about 95% carbohydratesIt is about 95% carbohydrates

It is mostly It is mostly glycoproteinsglycoproteins (proteins that are (proteins that are

bonded to carbohydratesbonded to carbohydrates

FunctionFunction

They hold cells togetherThey hold cells together

Fibers are woven together to make a Fibers are woven together to make a

networknetwork

The ECM binds to integrins (receptors that The ECM binds to integrins (receptors that

are in the plasma membrane) to are in the plasma membrane) to

communicate with the cytoskeletoncommunicate with the cytoskeleton

Changes in the cytoskeleton can signal Changes in the cytoskeleton can signal

chemical pathways in the cellchemical pathways in the cell

Analogy Analogy

Weaving a blanket of different types of Weaving a blanket of different types of

threads.threads.

The ECM is composed of multiple different The ECM is composed of multiple different

fibers that are woven together to form a fibers that are woven together to form a

structure that binds cells together.structure that binds cells together.

Intercellular Junctions

4 Types

Structure

• Tight Junctions- fuse together to create belts around the cell

• Desmosomes- fasten the cells together into strong sheets

• Gap Junctions- small channels between animal cells

• Plasmodesmata- small channels between plant cells

Function

• Tight Junctions- prevents leakage of

extracellular fluid

• Desmosomes- “anchoring junctions” fastens

cells into strong sheets

• Gap Junctions- “communicating junctions”

provide channels that allow small molecules to

pass between animal cells

• Plasmodesmata- provide channels that allow

small molecules to pass between plant cells

Analogy

• Gap junctions and Plasmodesmata are similar to the tunnel between Canada and the United States. The tunnel (channel) provides the cars (molecules) with a way to travel between the two countries (cells).