Biology 2201

Unit 1Matter and Energy

1Unit 1 Matter and Energy

Biology

• Definition:– Biology is the study of living organisms – Divided

into many specialized fields that cover their morphology, physiology, anatomy, behavior, origin and distribution.

Unit 1 Matter and Energy 2

Cells: An Introduction

HowStuffWorks "Cell Biology Videos"

Unit 1 Matter and Energy 3

Unicellular organisms

Unit 1 Matter and Energy 4

Multicellular

Unit 1 Matter and Energy 5

6Unit 1 Matter and Energy

Historical Development of Cell Theory

Cell Theory is composed of 4 main points:

1. All living organisms are composed of one or more cells.

2. Cells are the basic units of structure and function in all organisms.

3. All cells are derived from pre-existing cells.

4. In a multicellular organism, the activity of the entire organism depends on the total activity of its individual cells.

Spontanteous Generation (Abiogenesis)

Unit 1 Matter and Energy 7

Biogenesis

Unit 1 Matter and Energy 8

Significant Events in Biological History Relating to Cell Theory

For hundreds of years a debate raged amongst scientists about

the origin of living things. The debate centered around two

theories:

1. Abiogenesis (Spontaneous Generation)2. Biogenesis

Unit 1 Matter and Energy 9

Abiogenesis

- The idea that living organisms can arise from

nonliving matter.

- Many examples are sited by early scientists:- Appearance of mushrooms on logs

- Maggots forming on rotting meat

- Micro-organisms apprearing in a sterilized flask of meat

broth. (John Needham’s experiment)

Unit 1 Matter and Energy 10

Evidence for AbiogenesisEvidence that supported abiogenesis Fact or Fiction

• Maggots suddenly appeared on uncovered meat after several days

Fiction – Maggots were present, but only after the flies laid their eggs on the meat

• Frogs and salamanders suddenly appearing on or in mud

Fiction – These amphibians hibernate and burrow into the mud and come to the surface to eat

• Jan Baptista van Helmont said that mixing a dirty shirt with wheat grains would produce adult mice that would then mate.

Fiction – The mice that were attracted to the food source (wheat) arrived, and then mated. They possibly hid in the mixture

• John Needham’s experiment with meat broth teeming with microbes after being boiled.

Fiction – He did not boil the broth long enough to kill all the bacteria in the broth, and so they divided, making the broth cloudy.

Biogenesis

- The idea that living organisms can only come

from other living things.

- Scientifically shown to be correct by several

scientists.

Unit 1 Matter and Energy 12

Activity #1

• Create a timeline that depicts the accomplishments of the following scientists:

Unit 1 Matter and Energy 13

AristotleRediNeedhamSpallanzaniPasteurBrownSchleiden

SchwannBraunVirchow

HookeLeeuwenhoek

Francesco Redi (1688) performs an experiment to

show that maggots will not appear on rotting meat if

flies are kept away.

Unit 1 Matter and Energy 14

• Louis Pasteur (1860) designs and performs an experiment that shows that micro-organisms that appear in a sterilized meat broth actually come from micro-organisms found in the air and do not formspontaneously from the non-living broth.

Unit 1 Matter and Energy 15

Other scientist who contributed to the development of the Cell Theory:

Robert Hooke (1665) using a primitive set of

lenses to form a simple microscope, observes

“empty room like apartments” in samples of

once living tree bark. Hooke names these

compartments cells.

Unit 1 Matter and Energy 16

Anton Van Leeuwenhoek (1667) designs his own microscopes that are far more powerful than any of the primitive forms at the time. Over the next number of years Leeuwenhoek writes extensively about is observations of tiny organisms.

Unit 1 Matter and Energy 17

Mathias Jacob Schleiden (1883) writes, “all plants are made of cells”.

Theodor Shwann (1839) writes “all animals are made of cells” and “cells are organisms and entire animals and plants are collectives of these organisms”.

Rudolph Virchow (1858) formulates the points of the cell theory. Writes, “all cells come from pre-existing cells”.

Unit 1 Matter and Energy 18

Early Use of Microscopes

• Tendency to look at the known world• Magnified up to 50x the actual size• Most microscopes had 2 lenses doubling

the distortion of the poor quality lenses• Van Leeuwenhoek mastered lens craft in

is single-lens scopes achieve magnifications as high as 500x with little distortion

Van Leeuwenhoek’s microscope

Microscopes

Unit 1 Matter and Energy 20

Microscope Imaging of Today

• Compound light microscopes– Max. magnification of about 2000X– Can see most but not all cells, and cell structures– Resolution limited to about 0.2 µm– Resolving power is limiting, so the light source must be

changed to accommodate this

• Electron microscopes– Use a beam of electrons instead of light to magnify objects– Use electromagnets to focus beams instead of lenses

Using a Microscope to Explore the Cell

• Resolution or Resolving power – The ability of the eye, or other instrument, to distinguish

between two objects that are close together

High resolution Low resolution

Compound Light Microscope

Unit 1 Matter and Energy 23

Completely Label the microscope using pg. 16 in your textbook.

Compound Light Microscope Parts

Condenser lens

See page 16 in your textbook

Viewing Prepared Slides 1. Put low power objective lens in place2. Lower the stage with coarse adjustment.3. Adjust the diaphragm for brightest light.4. Place the specimen on the stage and clip in place.5. Focus with course adjective.6. Change to Med. Power and focus with fine adjustment.7. Change to high power and focus with fine adjustment

only.

Unit 1 Matter and Energy 25

Biological Drawing

Unit 1 Matter and Energy 26

Transmission Electron Microscopes(TEM)

Unit 1 Matter and Energy 27

Transmission Electron Microscope

• Directs a beam of tiny particles (electrons) through an object.

• It uses magnets rather than lenses and the result is shown or projected on a screen because the eye cannot respond to electrons.

Unit 1 Matter and Energy 28

Transmission Electron Microscope

• The problem with this microscope is that the object being viewed must undergo extensive preparation.

• It must be very thin and as it is prepared, it is sliced frozen and treated with chemicals which may distort the image.

• The magnification is 1,000,000 x.

Unit 1 Matter and Energy 29

Scanning Electron Microscope (SEM)

Unit 1 Matter and Energy 30

Scanning Electron Microscope (SEM)

Unit 1 Matter and Energy 31

Light Vs Electron MicroscopesType Light Source Magnification Resolution Specimen Prep

Compound Light

Visible Light (light bulb)

Up to 2000x Aprox 0.2 micrometers

Killed, fixed and stained

Electron Beam of electrons

10 000-500 000 x (TEM)

1000- 10, 000 x (SEM)

o.2 nm (TEM)

1- 10 nm (SEM)

Killed, dried an fixed (TEM)

Killed, fixed, cleaned and coated with metal

Unit 1 Matter and Energy 32

Caring For and Using a Microscope

• LAB ACTIVITY PAGE 15 – 19

This must be completed in the class time provided

• Techniques covered in this lab will be on the test / exam

Magnification

• Multiply the power of the ocular lens by the power of the objective lens in place.

Low power mag = ________________Med power mag = ________________High power mag = ________________

Unit 1 Matter and Energy 34

Field of View (F of V)

Unit 1 Matter and Energy 35

Field of view is the size of the area you see when looking down a microscope.  For low power: place a ruler across the field of view and measure the diameter in millimeters.

F of V (low) =

Fof V (med) =

F of V (high) =

Characteristics of Living Cells:

1. obtain food and energy2. convert energy from an external source into a form

that the cell can use3. construct and maintain the molecules that make up

cell structures4. carry out chemical reactions5. eliminate wastes6. reproduce7. keep records of how to build structures

Unit 1 Matter and Energy 36

Cells

• KNOW Figure 1.11 in your text – you will be expected to label either the animal cell or plant cell (coming up later)

• You will also be expected to know the functions of all the parts of the cell and how they work together to help the cell function

Cells

There are two types of cells:

1. Prokaryotic cells- cells that have no nucleus

or membrane bound organelles. They are

smallest in size and are characteristic of the

simplest type of living things, bacteria.

Unit 1 Matter and Energy 38

Prokaryotic Cells

• Since they do not have a nucleus, all the genetic information is concentrated in an area called the nucleoid. Some prokaryotic cells also have a small ring of DNA called a plasmid

• Prokaryotic cells move using flagella• See Fig. 1.22 on page 33

Prokaryotic Cell (Bacterial)Draw this!

Unit 1 Matter and Energy 40

2. Eukaryotic Cells – cells that contain a distinct

nucleus and have membrane bound organelles.

They are found in more complex unicellular

organisms and all multicellular organisms.

Eukaryotic cells have distinct parts that are

responsible for carrying out certain functions

within the cell. These are called organelles.

Unit 1 Matter and Energy 41

Organelles work together to carry out basic life processes. Eukaryotic cells display what is known as a division of labour.

Within all eukaryotic cells, there are several distinct areas:

- The cell membrane- The nucleus- The Cytoplasm

Unit 1 Matter and Energy 42

The Eukaryotic Animal Cell (DRAW THIS!)

Unit 1 Matter and Energy 43

The Eukaryotic Plant Cell(Draw This)

Unit 1 Matter and Energy 44

Plant Cells vs. Animal Cell• Plant cells contain many of the same structures

as animal cells, but there are some differences:• plant cells have an outer cell wall made of

cellulose; animal cells do not– Provides rigidity and protection

• Plant cells have one large central vacuole; animal cells have several vacuoles

– Provides rigidity and stores wastes, nutrients and is filled with water

• Animal cells have a centrosome; plant cells do not

– Involved in animal cell division• Plant cells have chloroplasts; animal cells do not

– chloroplast – plastid that gives green plants their colour and transfers energy in sunlight into stored energy in carbohydrates during photosynthesis

1. The Cell Membrane-

“The Control Gate”.

- Composed of a double layer of lipids (fats), with proteins

embedded in these layers.

- The cell membrane is selectively permeable. This means

that some substances can pass through it and enter the cell,

while other substances cannot pass through. This allows the

membrane to maintain homeostasis- keeping the internal

physiological environment of the cell constant.

Unit 1 Matter and Energy 46

2. The Nucleus-

“ The Command Center”. It controls most activity in the

cell.

The nucleus contains chromatin- uncoiled chromosomes

that contain DNA. The DNA contains the information

required for proper functioning of the cell.

The nucleus also contains a darkened structure known as

the nucleolus- responsible of production of ribosomes.Unit 1 Matter and Energy 47

• The nuclear envelope surrounds the nucleus and has

pores that allow materials to enter and leave the

nucleus.

3. The Cytoplasm-

The gel-like portion of the cell that contains each of the

cells organelles. The liquid of the cytoplasm also contains

many dissolved substances that creates a chemical

environment necessary for proper functioning of the cell

structures.

Unit 1 Matter and Energy 48

Organelles in BOTH plant and animal cells

Unit 1 Matter and Energy 49

-Ribosomes- spherical two-part

structures that play a role in the

production of proteins. Located on the

E.R or the cytoplasm.

-Endoplasm Reticulum (E.R)- These

structures are involved in the transport of

proteins through the cell. It’s made of

folded membrane. May be rough, which

means it is covered with ribosomes, or

smooth, which means it has no

ribosomes

The proteins that are made from the

ribosomes on the rough ER are transported

from rough to smooth ER then forms a bubble

and pinches off, forming a vesicle. This vesicle

transports the protein to the Golgi Apparatus.

- Vesicles- small transport sacs.

Unit 1 Matter and Energy 50

• Golgi Apparatus- These structures are involved

in the refinement, packaging and shipping of

proteins for the purpose of excretion.

• Mitochondria- The “power house”. These

structures break down simple carbohydrates in

order to release their energy. This is called

cellular respiration.

Unit 1 Matter and Energy 51

• Vacuoles- areas of storage within the cell for

water and other substances. In plants, these

can be quite large.

- Centrioles- involved in cell reproduction. They

ensure even distribution of cell components

when the cell divides. Located in centrosome.Unit 1 Matter and Energy 52

- Lysosomes- “The Recycling Center”. These

structures are involved in the breakdown of

large particles as well as warn out cell parts.

Organelles found ONLY IN PLANT CELLS:

- Cell Wall- This structure is composed of

cellulose and surrounds the cell membrane.

Unit 1 Matter and Energy 53

The function of the wall is to give support and

shape to plant cells.

- Plastids, including chloroplasts and

chromoplasts, are involved in the trapping of

sunlight and the process of photosynthesis.

-Central Vacuole- Provides support and storage

for food, water and toxins. It’s large and fluid-

filled.

Unit 1 Matter and Energy 54

The Cell Membrane

• In order for a cell to carry out its life functions, it must be able to get raw materials from its environment and regulate the movement of materials into and out of the cell.

• Recall: the cell membrane is SELECTIVELY PERMEABLE!!!

Functions of the Cell Membrane

1. Transport raw materials into the cell.2. Transport manufactured products and

wastes out of the cell.3. Prevent entry of unwanted materials into

the cell.4. Prevent escape of matter needed to perform

cellular functions.

Unit 1 Matter and Energy 57

Cell Membrane function:

A living cell must maintain a good internal environment or homeostasis. This

homeostasis refers to maintaining nearly constant internal conditions so that

the cell can perform its life functions. It is a process of keeping a balance of

solutes and solvent within a cell. The environment of the cell interior is kept at

a steady state despite changes in the conditions of the external environment.

Materials have to pass into or out of the cell membrane. The cell membrane is

said to be selectively permeable, allowing some molecules to pass through it

while preventing others from doing so. The cells of a multicellular organism

are bathed in a thin layer of extracellular fluid, containing a mixture of water

and dissolved materials. Dissolved materials such as nutrients and oxygen can

enter into a cell while other materials such as wastes and carbon dioxide can

leave a cell.

Cell Membrane Structure

• The cell membrane is a DOUBLE LAYER of PHOSPHOLIPIDS with PROTEINS embedded throughout.

THE FLUID-MOSAIC MEMBRANE MODEL

The phospholipid bilayer contains a mosaic of different components scattered throughout it, like raisins in slice of bread. But, the proteins that are embedded are able to drift sideways, hence the term fluid-mosaic.

Components of the Cell Membrane

• Phospholipid Bilayer- Contains a phosphate “head” that is water-loving or hydrophillic, and two fatty acid “tails” that are hydrophobic, or water-hating. The heads are soluble in water while the tails are insoluble.

• Draw:

Components of Cell Membrane con’t

• The Proteins are used mainly for transporting various materials in and out of cells.

• Cholesterol- is a lipid that is also embedded throughout the membrane allowing the cell to funtion in a wide range of temperatures.

• Carbohydrate Chains- like the “fingerprint” of the cell, it distinguishes one cell from another.

Drawing of a Cell Membrane

Transport Across the Cell Membrane

There are two broad categories of transport across the cell membrane:

• Passive Transport (Requires NO ENERGY)• Active Transport (ENERGY REQUIRED)

Passive Transport:

Three ways this occurs:

– Simple Diffusion– Facilitated Diffusion– Osmosis

Unit 1 Matter and Energy 64

Simple Diffusion

Unit 1 Matter and Energy 65

Diffusion Examples

Unit 1 Matter and Energy 66

Diffusion of oxygen into the cell

Facilitated Diffusion

• Diffusion of substances that need to be “helped” across the membrane! Sugars and charged iors like sodium and chloride.

Unit 1 Matter and Energy 67

Osmosis

• The diffusion of water across the cell membrane. Results in three conditions:

1. Isotonic Conditions2. Hypotonic conditions3. Hypertonic conditions

Unit 1 Matter and Energy 68

Isotonic conditions

Unit 1 Matter and Energy 69

Hypotonic conditions

Unit 1 Matter and Energy 70

Hypertonic Conditions

Unit 1 Matter and Energy 71

Overview of Osmosis effect on cells

Unit 1 Matter and Energy 72

Active Transport

• When a cell must spend energy in order to move materials against the concentration gradient.

• Active transport involves moving materials from areas of low concentration to high concentration through a transport “pump” in the membrane. Energy in the form of ATP is used to work the pump.

Active Transport

Examples of Active Transport

• At rest, 40% of your energy is being used to perform active transport!

• How?– Kidney cells move glucose (sugar) and amino acids

(building blocks of proteins) into the bloodstream.– Intestinal cells move nutrients in from the gut.

More examples…

• Root cells of plants move nutrients from soil into the plant cells.

• Gill cells of fish pump out sodium ions.

Compare Active and Passive Transport

Unit 1 Matter and Energy 77

Active Transport Passive Transport

Similarities particles enter and exit the particles enter and exit thecell cell

proteins in the membrane act

proteins in the membrane act

as “doorways” as “doorways” for some

particles

Differences particles move against the particles move with theconcentration gradient concentration gradient

cellular energy is used tono cellular energy is

needed

move particles to move particles

Bulk Membrane Transport

• Occurs by active transport.• Molecules that are too large are moved across

the membrane by way of the membrane folding in on itself to create a membrane-enclosed, bubble-like sac, called a vesicle

• Draw…

Bulk Membrane Transport

Bulk Membrane Transport

• When materials enter the cell in this manner, it’s called Endocytosis.

• When materials exit the cell in this manner it’s called Exocytosis.

Three kinds of Endo/Exocytosis

1. Pinocytosis- “Cell drinking”. Here, the cell takes in extracellular fluid that has dissolved particles, as if drinking.

2. Phagocytosis- “Cell eating”. Here, the cell takes in extracellular fluid that contains particulate or organic matter in it.

3. Receptor-Assisted/Mediated- The cell membrane has receptor proteins that attaches to specific molecules to transport. Like a lock and key, the molecules must match the receptor site.

Why are cells so small?

• EFFICIENCY!• It is more efficient for cells to diffuse materials

across the cell membrane over short distances. So, having trillions of small cells (as opposed to one large one) provides the best amount of cell membrane over which to transport materials in and out of the cell.

Unit 1 Matter and Energy 83

Surface Area: Volume

Unit 1 Matter and Energy 84

One Large Cell VS Many Small Cells

Unit 1 Matter and Energy 85

Cells, Matter and Energy

• All organisms are composed of cells. They all need food to provide the energy and matter they need for growth and reproduction.

Unit 1 Matter and Energy 87

The energy that is utilized by a cell has to come from an outside source. In terms of the makeup of feeding relationships for organisms, the basis of all energy will be the SUN. In an ecological relationship, the sun is needed to provide the energy that producers need to make their own food by the process of PHOTOSYNTHESIS. The producers ( green plants, algae and some kinds of bacteria) undergo photosynthesis and are known as AUTOTROPHS . Autotrophs become food for other organisms known as HETEROTROPHS — obtain food from other sources.

Chemical Energy in Cells

• Cells control the chemical reactions occurring within. With every chem rxn, there is an energy transformation (a change from one form to another).

• The total of all the chemical reactions that occur within a cell is known as its METABOLISM.

METABOLISM

• Includes all the building up and breaking down of substances in a cell in addition to the energy transformations that occur simultaneously.

TWO MAJOR PROCESSES THAT PROVIDES CELLS WITH ENERGY:

• 1. Photosynthesis• 2. Cellular Respiration

Unit 1 Matter and Energy 90

Energy Transformations in Cells

• 1. Photosynthesis:– Occurs in chloroplasts of plant cells. The

chlorophyll absorbs light energy and give leaves their green colour.

– Light energy is used to transform carbon dioxide and water into energy-rich food.

CO2 + H2O C6H12O6 + O2

Energy Transformations con’t

• 2. Aerobic Cellular Respiration:– A series of chemical reactions that break down

(metabolize) carbohydrates and other molecules in order to release the energy they contain.

– Occurs in the MITOCHONDRIA of cells.

PS and CR are COMPLEMENTARY!

Unit 1 Matter and Energy 94

Comparison of PS and CR

Process Raw Materials Products Location

photosynthesis carbon dioxide sugar

water oxygenChloroplasts of Plant

Cells

energy

respiration sugar carbon dioxide

oxygen waterMitochondria of

Animals and plants

energy

Unit 1 Matter and Energy 95

Global Implications of Photosynthesis (PS) and Cellular Respiration(CR)

• The energy transformations that occur in PS and CR are important for several reasons:

1. Autotrophs- manufacture their own food through PS. They form the basis of all food chains.

Unit 1 Matter and Energy 97

2. Heterotrophs- These organisms must eat to obtain nutrients, therefore they depend indirectly on PS for food. They also depend on CR to release energy from their food.

3. Environment- PS and CR are important parts of the carbon cycle that recycles carbon throughout the land, water and atmosphere.

4. Industry- The economy is driven mainly by agriculture, fishing, forestry and mining. PS and CR play key roles in each.Agriculture and forestry- depend on plants to provide food, construction materials, fabrics,and pharmaceuticals.Fishery- The fish depend phytoplankton to perform PS to provide food. The fishers in turn catch the fish.

Mining- The fossil fuels being mined today were once ancient forests and oceanbeds.