Unit 1

Life On A Cellular Level

Important Cellular Biologists and Important Cellular Biologists and Their DiscoveriesTheir Discoveries

• Robert Hooke Robert Hooke first person to see cells in cork; first person to see cells in cork; named a cell a cellnamed a cell a cell

• Anton Van Leeuwenhoek Anton Van Leeuwenhoek developed the first light developed the first light microscope; observed microorganisms in pond microscope; observed microorganisms in pond waterwater

• Mathias Schleidan Mathias Schleidan stated that plants are made up stated that plants are made up of cellsof cells

• Theodor Schwann Theodor Schwann stated that animals are made stated that animals are made up of cellsup of cells

• Rudolph Virchow Rudolph Virchow all cells come from other cells all cells come from other cells (life comes from life)(life comes from life)

• Robert Brown Robert Brown first to see a “dark spot” now called first to see a “dark spot” now called a nucleusa nucleus

Cell TheoryCell Theory• 1) All organisms are composed of one or more 1) All organisms are composed of one or more

cells.cells.– An organism may be a single cell, such as an An organism may be a single cell, such as an AmoebaAmoeba

or a bacterium. Larger organisms, such as humans, or a bacterium. Larger organisms, such as humans, are composed of many cells.are composed of many cells.

• 2) The cell is the basic unit of structure and 2) The cell is the basic unit of structure and function in organisms.function in organisms.– In the same way that the basic unit of matter is the In the same way that the basic unit of matter is the

atomatom, the basic unit of life is the , the basic unit of life is the cellcell..

• 3) All cells come from pre-existing cells.3) All cells come from pre-existing cells.– Cells come from the reproduction of previously existing Cells come from the reproduction of previously existing

cellscells

Two types of cells: ProkaryoticTwo types of cells: Prokaryotic1) Prokaryotes (before 1) Prokaryotes (before

nucleus)nucleus)– Cells that do not have a Cells that do not have a

nucleusnucleus– Carry out all life Carry out all life

processes without a processes without a nucleusnucleus

– Have Cell Wall!!!Have Cell Wall!!!– Simple cells (unicellular) Simple cells (unicellular)

and are smaller than and are smaller than eukaryoteseukaryotes

– Genetic material in Genetic material in CytoplasmCytoplasm

– 2 billion years older than 2 billion years older than euk. euk.

– Ex. Kingdom Monera Ex. Kingdom Monera bacteriabacteria

Eukaryotic Cells (animal cells)Eukaryotic Cells (animal cells)

22) Eukaryotes (have nucleus)) Eukaryotes (have nucleus) Cells that do have a nucleusCells that do have a nucleus More complex than More complex than

prokaryotes prokaryotes 10 times larger than prok.10 times larger than prok. Unicellular and multicellularUnicellular and multicellular Genetic material in nucleusGenetic material in nucleus Ex. all other kingdoms Ex. all other kingdoms

fungi, protozoa, plants, and fungi, protozoa, plants, and animalsanimals

Them Them vsvs. Us –. Us –Prokaryotes and EukaryotesProkaryotes and Eukaryotes

Animal Cells Plant Animal Cells Plant CellsCells

CentriolesCentriolesCell WallCell Wall

ChloroplastsChloroplasts

Cell Cell membrane membrane Ribosomes Ribosomes Nucleus Nucleus ER ER Golgi Golgi apparatus apparatus Lysosome Lysosome Vacuoles Vacuoles Mitochondria Mitochondria CytoskeletonCytoskeleton

CELL CONCEPT MAP

CELL

Consists of

Cel wall (plant cell)

Cell membrane Protoplasm Vacuole (plant cell )

of two parts

NucleusCytoplasm

contains Consists of

Nuclear membrane

Nucleoplasma

contains

Chromatin substances / chromosomes

Consists of

Protein (histone)

DNA

Cell organelles

Mitocondrion Chloroplast (in green plant)

Endoplasmic reticulum

Rough ER Smooth ER

Golgi Body

Fluid medium, (containing nucleotides and enzymes)

Grana StromaRibosome

Basic unit of life. All organisms consists of cell

Procaryote and eucaryote- 2 types

Microbodies contained in the cytoplasm, carrying out specific functions for the cell activities

Processing and packaging proteins/ other molecules to form cell secretions

Contains water, nutrients, mineral salts, waste (nitrogenous) substances

The site for protein synthesis

Generates energy for the cell

The fluid mosaic hypothesis- the bilayer of phospholipid molecules with protein molecules in it / over the surface

Made up from cellulose, porous to micro- and macromolecules like sugar and starch

Contains chlorophyll

Contains enzymes With

ribosomesNo

ribosomes

What do you know about the cells?

Cell Parts and Functions

Cell Membrane

Protects the cell

Lets things in and out of the cell

Location: around the cell

Nucleus

Control center

Location: inside the cell,

near the center

Cell Parts and FunctionsNucleolus (Nucleoli)Makes ribosomesLocation: inside the nucleus (dark spot)

Nuclear MembraneProtects nucleusLets things in/out of nucleus (pores)Location: around nucleus

cell

Cell Parts and FunctionsMitochondria

Makes energy/powerhouse

Location: in cytoplasm

Golgi Bodies/Apparatus

Packages and secretes

(gets rid of) waste

Location: in cytoplasm

Mitochondria

GOLGI APPARATUS

Cell Parts and Functions

Endoplasmic Reticulum (E.R.)Transports materials and sends messages to all

parts of the cell

Two types: smooth and rough (has ribosomes)

Location: attaches from cell membrane to nuclear membrane

Rough E.R.

Cell Parts and Functions

Ribosome

Makes proteins

Location: in cytoplasm or

Attached to E.R.

Vacuole

Stores food and water

Location: in cytoplasm

Vacuole

Cell Parts and Functions

Lysosome

Contains digestive enzymes

Destroys bacteria, old cell parts…

Location: in cytoplasm

Centrioles

Helps the cell to divide

Location: in cytoplasm

Cell Parts and Functions

Cytoplasm

Gel-like substances, holds all

Organelles in cell

Location: in cell

Chromatin/Chromosomes

Contains genetic information/traits

Location: in nucleus

Cell Parts and FunctionsCiliaShort hair-like projections Used for movementLocation: outside of cell

FlagellaLong whip-like tailUsed for movementLocation: outside of cell

FLAGELLA

Cell Structures and FunctionsChloroplast

Traps suns energy and

Makes food

Location: in plant cells

Cell Wall

Cell Wall

Protects and supports plant

Cells

Prevents water loss

Cellulose

Location: outer layer of plant cells

CYTOSKELETON

Function: Support structure of cell and transport materials/organelles throughout

the cell.

The highway of the cell.

Made of Microtubules (thin hollow cylinders) and Microfilaments (thin solid cylinders)

Location: Inside the cell

CYTOSKELETON

Cell Structures and Functions

Plastids

Stores extra food in

Plant cells

Location: in plant cell

Plant vs. Animal Cell

http://www.cellsalive.com/

Levels of OrganizationLevels of Organization• In a multicellular In a multicellular

organism: cell, organism: cell, tissues, organs, organ tissues, organs, organ system, that make up system, that make up an organisman organism

• Tissue – main types Tissue – main types of tissueof tissue– 1) muscle1) muscle– 2) epithelial2) epithelial– 3) nerve3) nerve– 4) connective4) connective

• Organs – many tissues Organs – many tissues make up an organmake up an organ– Each tissue has a Each tissue has a

specific function to specific function to help an organ workhelp an organ work

• Organ System – Organ System – – 10 organ system in 10 organ system in

the human bodythe human body– Each level makes the Each level makes the

division of labor division of labor among those cells among those cells possible for life of possible for life of multicellular multicellular organismsorganisms

A.DNA

B.Enzymes

C.Lysosomes

D.Ribosomes

A.Lysosomes

B.Mitochondria

C.Golgi bodies

D.Centrioles

A.Mitochondrion

B.Ribosome

C.Lysosome

D.Golgi body