CHAPTER 6:Life is Cellular

I. History of CellsA. Microscopes

1. Merchants first used hand lens to

asses cloth quality

2. Hans & Zacharias Janssen (c. 1590)-

Dutch lens makers invented first

compound microscope

3. Robert Hook (1665)- used light

microscope to look at cork;

Saw tiny chambers that he called “cells”

4.Anton Van Leeuwenhoek-

one of the first to use

microscopes to observe

nature

• Tiny organisms in H2O

• “Animalcules”.. bacteria

B. Cell Theory 1. When? 1838-1939 a. Matthias Schleiden

– All plants made of cells

b. Theodor Schwann– All animals made of cells

2. Rudolf Virchow– Studied cell reproduction/cancer– All cells came from another cell

3. Cell Theory

a) All living things are composed of cells

b) Cells are basic units of structure and function in living things

c) New cells are produced from existing cells

II. Cell Types

A. Prokaryotes

1. Cells generally smaller

2. Do not have nuclei

3. Evolved first

4. All bacteria are prokaryotes• Ex: E. coli, staph

B. Eukaryotes 1. Contain nucleus 2. Cells are more complex- many eukaryotes form larger, multi-cellular organisms 3. Evolved after prokaryotes 4. Ex: Plants, animals, & fungi

III. Differences Between Plants & Animals

A. Plants Have (animals do not):

Cell wall, chloroplasts,

plastids, large central water

vacuole

B. Animals have (plants do not):

Centrioles, lysosomes

IV. Boundaries of the CellA. Plasma/Cell Membrane: - All cells

- Made of phospholipid monomers

- Double-layer, hydrophobic tails

in-between

- Hydrophilic heads line outside

and inside of cell

B. Cell Wall

- Plants only, used for support

and shape, protection

- Made of cellulose, hemicellulose,

and pectin

V. Cellular OrganizationA. Unicellular- “one cell”

1. Cell IS the organism

2. Must perform all functions of life, tend to be

more complex on a cellular basis than multi-

cell organisms

Ex: Include prokaryotes

& eukaryotes

B. Multi-cellular organisms

1. Cells do not live on their own

“Interdependent”

2. Each has a function for the

whole and cell specialization to

perform particular functions within organism•Ex: Pancreatic cells

C. 5 Levels of Organization1) Individual cells2) Tissues3) Organs4) Organ systems5) Organism

Cells• Specialization of functions• Nerve cells & muscle cells rely on other cells to

give them materials

Tissues• A group of similar cells that perform a particular

function

• Ex: cells in pancreas make digestive enzymes

• Most animals have 4 types of tissue:

»Muscle

»Epithelial

»Nervous

»Connective

Organs• Groups of tissues that

work together• Ex: muscle has

nerve cells & connective tissue

organ systems

• Group of organs that work together to perform a specific function

• 11 major organ systems in human body

END OF POWERPOINT

YOU MUST KNOW ALL THE ORGANELLES AND FUNCTIONS OF THE

STRUCTURES ON THE FOLLOWING SLIDES

Basic Cell Structures

• Typical cells are 5-50 μm

• Cell membrane–thin, flexible barrier around cell

• Cell wall–strong layer around cell membrane

(plants)–serve to protect and support

• Nucleus

–large structure containing cell’s genetic material and controls cell’s activities

• Cytoplasm

–material inside cell membrane but not including the nucleus

Basic Cell Structures

Cytoplasm

• Contains specialized cells called organelles that perform cellular functions

Notes on Chapter 7.2

Cell Structures

Cell wall

• Found in plants, algae, fungi, and almost all prokaryotes

» Animal cells do NOT have cell walls!

• Allow H2O, O2, CO2, and other substances to pass

• Function- to provide support & protection

• Made of CH2O’s and protein

• Plants- mostly cellulose

Nucleus

• Controls most cell processes• Contains hereditary information of DNA

» DNA codes to make proteins

• Chromatin» DNA bound to protein» spread throughout nucleus- condenses

during division

• Chromosomes» Distinct, thread-like, condensed chromatin» Contain genetic information

Nucleolus

• Small, dense region inside nucleus» Assembles ribosomes that make proteins

Nuclear Membrane» Double-membrane layer» Many pores to allow materials in and out- “doors”» RNA

Cytoskeleton

• Protein & calcium filaments»Act like skeleton, give shape»Cell movement

• Microtubules» hollow tubes; “tracks” that organelles use to

move» Important in cell division; separate

chromosomes» Cilia» Flagella

Microfilaments

• Give movement & support» Tough, flexible framework» Motor proteins move organelles

Ribosomes

• Made of RNA in nucleolus

• Assemble proteins

• “Workers”

Endoplasmic reticulum• “Conveyor belt”

» Makes cell membrane components» Modifies proteins» rough and smooth

• Rough ER- involved in synthesis of proteins

» Gets appearance by ribsomes

Ribosomes

• Smooth ER- does not have ribosomes on surface

» Makes lipids for cell membranes

Golgi Apparatus• “Quality control”

» Stack of membranes» Proteins made by RER move here» Enzymes modify carbohydrates and lipids

to proteins» Brings to the cell surface to be secreted

Lysosomes

• “Janitors”» Small, filled with enzymes» Break down lipids, carbohydrates, and

proteins into particles the cell uses» Break down old organelles

Vacuoles

• “Storage”» Store H2O, salts, proteins, CH2Os

• Support structures, like leaves and flowers» Plants often have a central, large vacuole

• Smaller vacuoles- “vesicles”

Chloroplasts

• “Solar panels”» Found in plants» Use energy from sunlight to make

energy/food- Glucose» “photosynthesis”

• Two envelope membranes» Stacks of membranes that hold green

pigment» DNA

Mitochondria

• “Power house”» Release energy from stored food

• Use energy to make high-energy compounds

» Cell growth, development, and movement

• 2 envelope membranes» DNA» Inherited from mom!

• Found in all eukaryotic cells

Cell as a factory

• Plasma membrane- “shipping/receiving department”• Cytoskeleton- “walls, roof, and beams”• Nucleus- “the control center, CEO”• Ribosome- “workers” • Golgi Apparatus- “Quality control” • Mitochondria and chloroplasts- “power sources”• Lysosomes- “janitors”