Chapter 4The Cell In Action

Pseudomonas aeruginosa

What would happen if…

•If a cell couldn’t exchange nutrients, vital materials, and waste with its environment

•If a factory’s power supply was cut off or if its supply of raw materials never arrived?

•If the factory could never get rid of its garbage?

HOW DO MATERIALS MOVE IN AND OUT OF CELLS?

Phosphoflourescent Injection of bacteria into macrophage sample

Diffusion

• Gelatin/Dye Experiment

• At first it is easy to see where the gelatin ends and the dye begins.

• What happens over time?

• Why does this happen?

Diffusion

• The particles of dye and gelatin slowly begin to mix because of diffusion.

• Diffusion – the movement of ___________________________________________________. (Until __________ is

reached or a __________ resists the process). • Note: all substances are made of particles of varying

size• In other words they travel from ______________ to

________________ until the crowds are __________________________________________________________.

Diffusion

Consider 2 rooms filled with people

Cell Membrane

Diffusionto

Equilibrium

Cell Membrane

• http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html

• http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html

• http://www.biologycorner.com/bio1/diffusion.html

• http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBooktransp.html#Cells%20and%20Diffusion

• http://highered.mcgraw-hill.com/olc/dl/120068/bio03.swf

• http://en.wikipedia.org/wiki/Diffusion

Equilibrium

• When the concentration of a substance on the outside of the semi-permeable membrane ________________________

________________ on the inside of the semi-permeable membrane.

• FACT – All organisms need water to live

• FACT – The cells of living organisms are surrounded by and filled with fluids that are made mostly of water.

OSMOSIS

• Osmosis – the diffusion of ________ through the cell membrane from ______________________

________________________________________

• FACT – water is made up of particles. Pure water has the highest concentration of water particles.

• How would you lower the concentration of pure water?

OSMOSIS JONES

The Cell and Osmosis

• Water particles will move from areas of high concentration to areas of lower concentration.

• The direction of flow depends only on the level of concentration.

h

H2O

H2O

H2O

H2O

H2O

H2O

H2O

H2O

H2OH2O

H2O

H2O NaCl

NaClNaCl

Osmosis

Diffusion

Osmosis links• http://zoology.okstate.edu/zoo_lrc/biol1114/tutorials/Flash/

Osmosis_Animation.htm

• http://www.stolaf.edu/people/giannini/flashanimat/transport/osmosis.swf

• http://www.tvdsb.on.ca/westmin/science/sbi3a1/Cells/Osmosis.htm•

http://www.mhhe.com/biosci/esp/2001_gbio/folder_structure/ce/m3/s3/cem3s3_3.htm

• http://www.bbc.co.uk/education/asguru/biology/01cellbiology/05pathways/10osmosis/index.shtml

Red Blood Cells

• Link to Red blood cell lysing

Plant Cells

Crossing Membranes Demo

• Try dried grapes – in pure water will swell up

• - in water mixed with a lot of sugar or salt it will shrink

• Do the iodine-water-starch demo in front of class

• Many particles, such as water and oxygen can diffuse though the semi-permeable phospholipid cell membrane because of their small size.

• But what happens to molecules that are too large such as sugars or amino acids?

Passive and Active Transport

In order to understand these types of transport you have to know that these types of transport ___________________

___________________________________; allowing particles to travel in and out.

1. The activities of a cell depend on the materials that enter and leave

the cell. 2. To stay alive, a CELL MUST EXCHANGE Materials such as

Food and Waste With Its ENVIRONMENT.

3.  These materials must cross the Cell Membrane.

4. Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE

can move in and out freely. 5. Large molecules like PROTEINS

AND CARBOHYDRATES CANNOT.

6. The Cell Membrane is SEMIPERMEABLE.

7. A SEMIPERMEABLE MEMBRANE OR SELECTIVELY PERMMEABLE ONLY ALLOWS

Certain molecules tp pass through

•

• Passive Transport – the diffusion of particle through the proteins.– ____________________________________– ____________________________________

– (just like diffusion but can only occur at the protein doorways)

Passive Transport

•

Active Transport

• Active Transport – the movement of particles through the protein doorways– ____________________________________

___________________________________– ___________________________________– ____________________________________

• ACTIVE TRANSPORT

- is especially IMPORTANT in MAINTAINING ION CONCENTRATION IN CELLS AND BETWEEN CELLS

• http://www.bbc.co.uk/education/asguru/biology/01cellbiology/05pathways/07passivefacilitated/index.shtml

Other Means of Transport• Endocytosis – the cell membrane

__________________________________ it in a vesicle

formed from the pinched off circular piece of cell membrane.

• Exocytosis – ____________are formed at the endoplasmic reticulum or at the golgi complex and carried to the ___________

__________ where the vesicle ____________________ the contents

of the vesicle

MINI QUIZ

1) What part of the cell do materials pass through to get into and out of the cell?

2) What is osmosis?

3) How do large molecules move through the cell (and at what structure)?

Why do you get hungry?

• It’s your body’s way of telling you that your cell’s need energy.

(Just like feeling the need to breathe it’s cells craving oxygen)

(and it all stops without the sun)

Nearly all the energy that fuels life ___________________

Its light is changed into food by plants through the process of photosynthesis.

The food that plants make not only supplies them with energy but also for organisms that that eat the plants.

It All Starts With the Sun

Photosynthesis

• Occurs inside of chlorophyll which is inside of chloroplasts

• _____________ _________________

_____________ _________________

______________ _________________

Light Energy

Light Energy

Glucose

• __________________________________

___________________________________

• Carbohydrates are a storable form of energy

Oxygen

The By-Products

Of Photosynthesis

• Necessary for all life

How is energy derived from Food?

• Food molecules (ie. Sugars) must be

__________________________________

• This is accomplished via 2 different processes:

1) _______________________

2) _______________________

Cellular Respiration

= aerobic respiration

– Uses _______________

– Glucose + Oxygen ________________________________

(The waste products of cellular respiration)

• Most of the energy released is in the form of heat. The rest is ATP.

• In eukaryotes the cellular respiration takes place in ______________________

Fermentation

= anaerobic glycolysis

- does not use oxygen

- leads to the production of small amounts of ATP

- produces by-product = lactic acid

Mini Quiz

True or False

1) Plants and animals capture their energy from the sun.

2) Cellular respiration describes how a cell breathes.

3) Fermentation produces ATP and lactic acid.

• The Cell Cycle

In the human body, 10,000,000 new cells are produced every

minute.

The cell cycle begins when the _____________ (or after the last division and ends _________________; at which point it begins again.

Note: The cell cycle does not end when the cell dies.

Before a cell divides it must:

• __________________

• __________________

• Done in the process of copying the chromosomes.

• How many chromosomes are there in a human? Fruit Fly? A potato?

• Human - 46 chromosomes» (23 pairs)

• Fruit Fly - 8 chromosomes» (4 pairs)

• Potato - 48 chromosomes» (24 pairs)

• The number of chromosomes has nothing to do with the complexity of an organism

Question???

What does DNA code for?

Prokaryotic Cell Division

• Cell division is called ________________.

• Simple because a bacteria only has a single circular DNA and some ribosomes

Eukaryotic Cell Division

More complex because there is so much DNA and because the DNA incorporates proteins into its structure.

3 stages of eukaryotic cell division

1) Stage 1 – The cell grows and copies its organelles and chromosomes

2) Stage 2 – Chromatid Separation = Mitosis

3) Stage 3 – Cell division into two cells identical to the original cell

_________ = eukaryotic cell division

• The process of _____________________

• Ensures that each cell receives a copy of each chromosome.

• 4 phases

Mitosis

• D____________

• L____________

• S____________

• Do demo with hands.

Definitions

Homologous Chromosomes (Pairs) – similar chromosomes which pair up during cell division. (ie. Humans have 46 chromosomes which are 23 pairs)

Chromatid – After each chromosome is duplicated the two copies are called chromatids

Centromere – the point at which the 2 chromatids are held together

Prior to Mitosis

• The ______________________ are copied

• At this stage each chromosome now consists of 2 chromatids.

• Centrioles are copied

Mitosis Stage 1 (Prophase)

• The nuclear membrane breaks down

• Chromosomes condense into compact structures

• Centrioles move to opposite sides of the cell

• Fibers form between the two centrioloe and connect to the centromeres of the chromsomes

Mitosis Stage 2 (Metaphase)

• The chromosomes are lined up along the equator (center of the cell)

Mitosis Stage 3 (Anaphase)

• The chromatids separate and are pulled to opposite sides of the cell by the fibers attached to the centrioles.

Mitosis Stage 4 (Telophase)

• Anuclear membrane forms around the now 2 sets of chromosomes.

• The chromosomes unwind

• The fibers disappear

After mitosis

• The ____________________ (cytokinesis)

• There are now 2 cells where there was once one. They are identical to each other.

Cytokinesis

• In animals – the membrane simply pinches off

• In plants – a cell plate forms in the middle of the dividing cell ad becomes the new membrane that will separate the 2 cells.

2 Chromosomes

*Parent Cell

Doubles to 4 chromosomes

“DUPLICATE”

“LINEATE”

“SEPARATE” = cytokinesis

*Daughter Cells

                                                                        

http://www.cellsalive.com/mitosis.htm

Mini Quiz

1) What is Cell Division?

2) How do prokaryotic cells make more cells (what is the process called)?

3) How do eukaryotic cells make more cells (what is the process called)?

Cell Division (Mitosis)

• Cell division allows an organism to :1) _______________2) _______________3) _______________

– Prior to division the cells copies its DNA– Cell Division is cellular reproduction– The daughter cell has the ____________ of

chromosomes as the parent cell.

Interphase

This is how all cells look before mitosis. Please be aware that Interphase is a phase of the cell cycle, but NOT a stage of mitosis.

• Mitosis - Early Prophase To begin mitosis, the nuclear membrane breaks down, while the chromosomes shorten and thicken (here, a chromosome is two chromatids, bound at a point called the centromere, making an "X" shape). The other structures important for mitosis are also forming (i.e. the centrioles).

• Mitosis - Metaphase The mitotic spindle apparatus has now formed and lies on the poles of the nucleus (but remember, the nuclear membrane has broken down, so there is no distinctly delineated nucleus). The chromosomes are lined up along the cell's equator, also known as the equatorial plate, and are attached to the mitotic spindle apparatus via microtubules (to try and visualize the microtubules extending from the poles to the chromosomes on the equator, think of the Earth - it's as if rope was extending from the chilly north and south poles to the chromosomes basking in the sun at the equator). Here's the confusing part - When the individual chromatids (½ of the "X") are separated from the chromosome (the "X"), they are now each referred to as a chromosome (i.e. In metaphase, the chromosome, composed of two chromatids, separates into the individual chromatids, which are then renamed chromosomes, even though they were only one half of a chromosome only moments before!) - Whew!

• Mitosis - Anaphase The newly formed chromosomes (which were recently chromatids while they were still ½ of the "X") are pulled along the microtubules toward opposite poles of the cell (like Monarch butterflies migrating back to Canada and the southern tip of South America (toward the poles) from Mexico (near the equator).

• Mitosis - Telophase • The chromosome

have finished their migration to the poles and the mitotic structures breakdown. The plasma membrane of the cell pinches down along the equator creating two separate cells (similar to twisting a long balloon and forcing it to pinch in the middle). At this time, the chromosomes become indistinct (as they are during Interphase), the nuclear membrane forms again and the nucleolus reappears.

Classification

Midterm Review

Lab Safety

• The number one rule is to Follow directions

Measuring

• In Science we use the metric system

Length –measured in metersMass – the amount of matter in a substance

- measured in grams- measured with a triple beam balance

Volume- the amount of space something occupies- measured in cm3 (solids)- measured in liters (liquids)- measured with a graduated cylinder

Temperature - measured in Celsius

Scientific Method

• Scientific Method – The orderly and universally accepted steps that a scientist uses to answer and solve problems.

1) Ask a question

2) Form a hypothesis

3) Test the hypothesis

4) Analyze the results

5) Draw Conclusions

6) Communicate the results

Scientific Method

1) Ask A Question – Good questions come from good observations. Observations are only useful if they are accurately made and recorded.– Tools to assist in observation

• Eyes, ears, noses, microscopes. Telescopes, graduated cylinders, clocks, rulers, etc.

Scientific Method

2) Form a Hypothesis – “educated guess”

You must think logically and creatively

Can you have different hypotheses for the same problem?

Scientific Method

3) Test the Hypothesisa) Controlled Experiment – one variable

1) variable- the single factor that is different or changed in an experiment

2) ‘If – Then’ statements3) Collect the Data4) Law of large numbers (number of tested groups

or the number of times an experiment is repeated)

Control – the group that does not receive the variable

Scientific Method

4) Analyze the Results

– organize the data (tables, graphs)

020406080

100

1stQtr

2ndQtr

3rdQtr

4thQtr

East

West

North

Scientific Method

• 5) Draw Conclusions – Do the results of the experiment support the hypothesis.

– If Not? What have you accomplished? You have proven and learned that the hypothesis is wrong.

» Options» Repeat» Find another explanation for what you have

observed

Scientific Method

6) Communicate the results – How?

You want to see if mice grow larger when they eat swiss cheese.

• Design an experiment to test this theory.

• State the hypothesis

• List the materials needed

• What steps would you take.

Characteristics of Life

• Living things sense and respond to change

• Living things reproduce

• Living things have DNA

• Living things use energy

• Living things grow and develop

Necessities of Life

• Food

• Air

• Water

• A place to live

Organization of Life

Cells

Tissues

Organs

Organ Systems

Organisms

Microscope

1) Made of 2 lenses which multiply magnification

a) Ocular lens or eyepiece

b) Objective lens

Magnification = ocular mag. x objective mag.

Cell Theory

1) Cells are the basic unit of life

2) All living organisms are made of 1 or more cells

3) All cells come from existing cells

Review Review

1) C Measures mass2) A Measures liquid volume3) D Measures centimeters4) B Measures Celsius5) A Measures milliliters6) C Measures grams7) D Measures length8) B Measures temperature9) D Measures meters10) C Measures the amount of matter in a

substance

11) 3 ml What is the volume in the cylinder?

12) 2.6 cm What is the length of the wooden block?

13) 4 Which group of measurements contains only metric units?

14) 4 Which lab equipment is correctly paired with a unit of measure?

15) C The amount of matter in a substance?16) A The basic unit in the metric system

used to measure mass?17) E An instrument used to measure the

volume of a liquid is a(n)?18) C A substance in outer space will have

no?19) E The prefix “centi” means?20) A The amount of space a substance

takes up is called its?

21)9.2 cm The earthworm is how many centimeters long?

A) 0.5 cmB) 5 cmC) 5.5 cmD) 6.5 cm

What are the masses?22) 175.7 g23) 622.9 g24) 286.2 g

What volume is indicated on each graduated cylinder?

25) 47 ml26) 32 ml27) 13 ml

What temperature is indicated on each thermometer?

28) 68°C29) -11°C30) 11°C

31) Scientists use a system of measurement called the metric system.

32) Length 2 cmwidth 2.5 cmheight 2 cmVolume 10 cm3

33) 25 mlWhat was the volume of the water before adding the rock?

34) 30 mlWhat is the volume of the water and the rock together?

35) How can you find out the volume of just the rock? Subtract (volume of water) from (volume of water + the rock).

36) 5 ml converts to 5 cm3 What is the volume of the rock?

Page 7-8

1) D A variable in the investigation2) B Which group was the control group3) C What hypothesis could be possible for this experiment4) B ( bad question)5) A What set of conditions must be kept the same through the

whole experiment6) E “We would like to find out which grow better”7) E “ I think bean plants grow better with fertilizer than without”8) D What sequence of steps is best9) E The experimental group with normal conditions used for

comparison10) B The single or one factor that is changed 11) B A way to test a hypothesis is to12) C The first step in the scientific method13) A ???14) D15) b

16) 2 Which was the control group?17) Sterilized What do we call anything boiled for

10 min. to kill bacteria18) D is the control and a,b,& c are the variable

groups19) Iodine20) Amount of iodine21) D because it had no iodine22) D the most and C the least23) The greater the amount of iodine the lesser the

populations of bacteria.

Page 11-12 (matching)1) Diffusion d2) Compound microscope j3) Chromosomes f4) Classification i5) Kingdoms b6) Magnification g7) Osmosis h8) Mitosis a9) Photosynthesis e10)Organic compounds c

11) Hypothesis i

12) Variable d

13) Experiment g

14) Control h

15) Osmosis b

16) Problem j

17) Diffusion e

18) Conclusion c

19) Molecules a

20) Information f

21) 1) respond to stimulus2) grow and develop3) have DNA4) reproduce5) Use energy6) have cells

22) 1) food2) air3) water4) a place to live

23) Photosynthesis and cellular respiration24) Consumption of food and cellular respiration25) Cellular respiration26) To build organelles and grow

27) slide, slip, specimen, water28) Flip it and turn it upside down29) Moves the opposite way 30) 1) position the specimen exactly in the center

of the field2) focus in med. Power3) refocus with fine focus4) turn the objective lenses

31) 1) follow directions2) goggles3) clean up spills4) never taste anything5) don’t wear dangling clothes or open toed

shoes

Scientific Method Questions1) Do irradiated radishes grow better2) Irradiated radishes will grow larger than normal ones3) Soil, light, water, control, experimental groups4) Radiation5a) normal radishes5b) soil, light, water6a) 1) hypothesis

2) experimenta) control groupb) experimental groupc) collect data

3) analyze data4) conclusion5) communicate results

6b) height of the plants in each group

7) Taller plants from irradiated beans

Would prove it

Cells Section1) Cell membrane

2) Nucleus

3) Chloroplasts or organelles

4) vacuole

5) cytoplasm

6) Cell wall

7) Cell membrane

8) Nucleus

9) Cytoplasm

10) vesicle

11) Other cells12) For cellular activities and building blocks13) Cell wall and chloroplast14) Cell15) 1 or more cells16) Nucleus17) Chloroplast18) Cell membrane19) Cell wall20) Cytoplasm or cytosol21) ER

22) Energy

23) Small enough to diffuse through the membrane

24) DNA structures

25) In the nucleus

26) Mitosis

27) Reproduction

28) a) Nucleus

b) Cytoplasm

c) cell membrane

29) Division

30) Reproduction and growth

31) Healing and replacement

32) Cells

33) Parent cell

34) Daughter cells

35) They are the same *****

36) Diffusion37) Tissues – organs – organ systems - organisms