CH 6:

A Tour of the Cell

6.1All organisms are made of cells

                                                                

                                                                                                           

Intro Info:

• Analogy: cells are to living things as atoms are to molecules

• All organisms are unicellular or multicellular

• B/C knowledge required microscopes…knowledge is fairly recent

3. Various types of MicroscopesLight Microscope

Electron Microscope (1950s)

(LM) (SEM)-surface(TEM)-internal

Magnifies up to 1000x

1,000,000x magnification

For bacteria or larger

Specimens must be killed

•Micrographs= photographs taken through a microscope

•Compound scopes= use two or more lenses

1. What evidence lead to the cell theory?

• 1st compound scopes used in 1600s• Robert Hooke ( 1665) 1st to describe

“compartments” aka cells• Leeuwenhoek made additional detailed

observations using precise lenses• All specimens observed were found to possess

cells

Cell History

2. Three main ideas of the Cell Theory

• 1800s evidence of observations led to cell theory– All living organisms are made of cells– Cells are the basic unit of structure and function

(what makes up and operates the organism)– All cells come from other cells

4. Similarities and Difference between Plant & Animal Cells

                                                                

                                                                                                           

                                                             

                                                                                                               P vs. A

4. Similarities and Difference between Plant & Animal Cells

Similarities DifferencesBoth types have Plasma Membrane

Only plant cells have chloroplasts

Both types have Cytoplasm

Only plant cells have cell walls

Both types have Nucleus

5. Eukaryotic vs. Prokaryotic Cells

SmallerLarger

Include BacteriaInclude animal cells, plant cells, fungi cells, protist cells

No nucleus or membrane bound organelles

Have a nucleus and organelles

Appeared on Earth 1stMore complex, appeared later

ProkaryoticEukaryotic E P

6.1 Vocabulary

• Cell theory• Micrograph• Organelle• Plasma membrane• Nucleus

• Cytoplasm• Cell wall • Prokaryotic cell• Eukaryotic cell

6.2Membranes organize a cell’s

activities

1. Describe the structure of cellular membranes

•Keep cell organized

•Regulate transport of substances

•Made of proteins and lipids (phospholipids-2 fatty acids)

•Double layer, one hydrophobic, other hydrophilic

•Allows boundaries between watery environments

2. Id the functions of the proteins found in the plasma membrane

• Proteins bind to specific molecules and help them move across a plasma membrane

6.2 Vocab

• Phospholipid bilayer

6.3Membranes regulate the traffic of

molecules

1. What is diffusion?

• Overall movement of particles from high concentration (crowded) to low concentration (open space)

2. What role does a cellular membrane play in passive transport

• Membranes allow certain particles to pass through (selectively permeable)– Dependent on size and electric charge

• Nonpolar pass easily• Polar (ions) do not

– Protein channels allow specific particles through

3. What is osmosis?

• Diffusion of water

4. Hypertonic vs. hypotonic vs. isotonic solutions

Hypertonic Hypotonic Isotonic

High concentration of solute

Low concentration of solute

Equal concentration of solute and solvent

Animals cell will shrivel

Animal cell will swell

Cell will not change

5. How is active transport different from passive transport? What is its

function?Active Transport Passive Transport

Is… Moving a solute against the concentration (from low to high)-requires energy

Diffusion (from high to low)--does NOT require energy

Function… To “accumulate” a particle

Allow movement of particles

6. How do vesicles transport large molecules?

• Exocytosis: vesicles will fuse with outer membrane and empty contents outside of cell

6.3 Vocab

• Diffusion• Equilibrium• Selectively permeable

membrane• Passive transport• Facilitated diffusion• Osmosis• hypertonic

• Hypotonic• Isotonic• Active transport• Vesicle• Exocytosis• endocytosis

6.4 Cells Build a Diversity of Products

1.In what ways does the cell nucleus direct the activities of the cell

• Nucleus:– Contains DNA– Contains dark

mass=nucleoulus (helps with ribosome productions)

– Membrane has pores for in/out

2. List how the functions of the ribosomes, ER, and golgi apparatus are related

Ribosomes ER: 2 types: Golgi ApparatusMake or produce proteins

Produce and transport proteins

Modify, store,or move proteins

Found on ER Smooth-no ribosomes on surface*build lipid molecules (hormones)

“processing or shipping center”

Rough-ribosomes on surface*common in cells that produce proteins

ER, Golgi,Ribosomes

3. Trace the path of a protein from the time it is produced by the

ribosome on the ER until it reaches its destination.

• Proteins ER ribosomes ER interior protein is captures into a vesicle moves to golgi processed and tranported to destination

3. What are the different functions of a vacuole and a lysosome?

Vacuoles Lysosomes Membrane Pathways

Membrane “sac” Membrane sac that digests molecules

Package, move, and transfer molecules in/out

Store undigested nutrients

Help nourish(feed) cells

Plants= 1 largeAnimals=many small

protect against bacteria, recycle damaged organelles

Vacuoles vs. Lysosomes

4. How are undigested nutrients in a vacuole made available to a cell

• Lysosome fuses with vacuole, releasing digestive enzymes which converts nutrients into substances cell can use.

6.4 Vocab

• Nuclear envelope• Nucleolus• Ribosome• Endoplasmic

Reticulum

• Golgi apparatus• Vacuole• lysosome

6.5Chloroplasts and Mitochondria

energize the cells

1. How are the functions of the chloroplasts and mitochondria similar?

Chloroplasts MitochondriaFound: In plants and

algaeIn all eukaryotic cells

Function: Trap light and convert it to energy (photosynthesis)

Performs cellular respiration: releases energy from sugars into ATP

Structure: Double membrane structure

Double membrane structure

2. How does a cell use the energy produced by the mitochondria

• In the chemical form of ATP

3. In what way is energy changed by reactions in a chloroplast?

• Light energy is changed/converted to chemical energy (as organic molecules)

4. How is membrane structure important to the functions of

mitochondria and chloroplasts.

• Both have double membrane structure– Chemical reactions take place

between inner and outer membranes

– Folded membranes also increase surface area

6.5 Vocab

• Chloroplast• Mitochondria• ATP

6.6An internal skeleton supports the cell

and enables its movement

1. What is the role of the cytoskeleton in cell movement

Cytoskeleton:

-Network of fibers that give cell internal support-made of two structures

Microtubules Microfilaments

give cell shape allow organelles to move within cell

2. How do microfilaments function in the cytoskeleton of a cell

Microtubules Microfilaments

give cell shape allow organelles to move within cell

Picture

3. How do flagella differ in structure and function from cilia?

Flagella Cilia•Both help with cell movement

•Tail-like structures•Usually only 1-2•Move in S shape

•Short hair-like•Usually lots of them•Row like oars

4. Give an example of coordination within a cell.

• DNA instructs ribosomes to make proteins• Proteins are made and move through

membrane pathways (ER and golgi)• Proteins are inserted into cell membrane to

aid is transport

6.6 Vocab

• Microtubule• Microfilament• Flagella• cilia