AS YOU COME IN, Materials:

PICK UP A COPY OF THE LABNotes pages and pencil

The Plan:Macromolecule reviewMacromolecule QuizBegin Eggcellent LabTake Energy in a Cell notes

The Assessment:Cell Organelle Quiz on Monday

FLAGELLA AND CILIAMicrotubules that allow

these single-celled organisms (protists) to

move.

MACROMOLECULE REVIEW General Information:

Organic vs. inorganic moleculesMonomer vs. polymerDehydration synthesis vs. hydrolysisCarbohydrate monomer, function,

testLipid monomer, function, testProtein monomer, bonds, function,

testNucleic acid monomer, monomer

parts, function

ENERGY AND THE CELL

Energy of Chemical Reactions• Basics of Energy• Enzymes & Substrates

Movement of Substances• Passive Transport:

Diffusion & Osmosis• Active Transport:

Proteins, Exocytosis, & Endocytosis

Energy Organelles• Chloroplasts• Mitochondria

Energy is defined as the capacity to do work

All organisms require energy to stay alive

Energy makes change possible, for example chemical changes

Two types of energy:Kinetic Energy: energy that is actually doing work

Potential Energy: stored energy

BASICS OF ENERGY

First law of thermodynamics“Law of Conservation of Energy”Energy can be changed from one form to another

Energy cannot be created or destroyed

Second law of thermodynamicsEnergy changes are not 100% efficient

BASICS OF ENERGY

Cells carry out thousands of chemical reactions The sum of these reactions constitutes cellular metabolism

BASICS OF ENERGY

There are two types of chemical reactions:1. Endergonic reactions absorb energy and

yield products rich in potential energy AKA: Endothermic reactions

Reactants

Po

ten

tia

l en

erg

y o

f m

ole

cule

s Products

Amount of energy INPUT

BASICS OF ENERGY

2. Exergonic reactions release energy and yield products that contain less potential energy than the reactants

AKA: Exothermic reactions

Reactants

Po

ten

tia

l en

erg

y o

f m

ole

cule

s

Products

Amount of energy OUTPUT

BASICS OF ENERGY

ENZYMESBiological catalysts

Lower activation energy needed for a chemical

reaction in the cell

11

Most enzymes are proteins (tertiary and quaternary structures)

Act as catalyst to accelerate a reaction

Not permanently changed in the process

ENZYMES

12

Are specific for what they will catalyze

Are reusable End in –ase

SucraseLactaseMaltase

ENZYMES

ENZYME

13

Enzymes work by weakening bonds which lowers activation energy

ENZYMES

14

FreeEnergy

Progress of the reaction

Reactants

Products

Free energy of activation

Without Enzyme

With Enzyme

ENZYMES

15

The substance (reactant) an enzyme acts on is the substrate.

EnzymeSubstrate Joins

ENZYMES

Forms an Enzyme-Substrate Complex

16

Active Site: A restricted region of an enzyme molecule which binds to the substrate.

EnzymeSubstrate

Active Site

ENZYMES

17

Enzymes are specific. The shape of the active site only fits a certain substrate.An enzyme that hydrolyzes protein will not

act on starch.

EnzymeSubstrate

Active Site

ENZYMES

18

Induced fit: A change in the shape of an enzyme’s active site

Induced by the substrate

ENZYMES

19

WHAT AFFECTS ENZYME ACTIVITY?

Environmental ConditionsExtreme temperatures are most dangerous

(high temp can denature (unfold) the enzyme)pH (need to remain 6-8)Tonic concentration (salt ions)

Enzyme InhibitorsCompetitive Inhibitors: chemicals that look like

the normal substrate and compete for the active site

Noncompetitive Inhibitors: chemicals that do not enter the active site but bind to another part of the enzyme causing the enzyme to change shape.

ENZYMES

20

COMPETITIVE INHIBITOR

EnzymeSubstrate

21

Enzyme

active site altered

NoncompetitiveInhibitorSubstrate

NONCOMPETITIVE INHIBITOR

AS YOU COME IN, Materials:

Notes pages and pencilEggcellent Lab PICK UP 5 PIECES OF PAPER

The Plan:Macromolecule Quiz – return papersDay 1: Eggcellent LabTake Energy in a Cell notesStart Cell Organelle flipbook

The Assessment:Cell Organelle Quiz on Monday

MOVEMENT OF

SUBSTANCESMoving necessary molecules into and

out of the cell through the cell

membrane

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Function: Cell membranes organize the chemical reactions making up metabolism by controlling the flow of substances into and out of the cell.

Membranes are selectively permeable.

CELL MEMBRANE

Phospholipids are the main structural components of membranes

Membrane phospholipids form a bilayer

They each have a hydrophilic (polar) head and two hydrophobic (nonpolar) tails

Head

Symbol

Tails

CELL MEMBRANE

In water, phospholipids form a stable bilayerThe heads face outward and the tails face

inward

Hydrophilicheads

Hydrophobictails

Water

Water

CELL MEMBRANE

The membrane is a fluid mosaic of phospholipids and proteins

Phospholipid molecules form a flexible bilayerCholesterol and protein molecules are

embedded in it Carbohydrates act as cell identification tags

CELL MEMBRANE

The plasma membrane of an animal cell

Fibers of the extracellular matrix

Glycoprotein Carbohydrate (of glycoprotein)

Microfilaments of the cytoskeleton

Phospholipid

Cholesterol

Proteins

CYTOPLASM

Glycolipid

Proteins make the membrane a mosaic of functionSome form cell junctionsOthers transport substances across the membraneSome are receptors for chemical messages

Transport

CELL MEMBRANE

Enzyme activity Signal transduction

Activated molecule

Messenger molecule

Receptor

FOCUS: Transport Passive transport Active transport

In passive transport, substances diffuse through membranes without work by the cell A type of diffusion Substances spread

from areas of high concentration to areas of lower concentration

EQUILIBRIUMMolecule of dye

Membrane

EQUILIBRIUM

CELL MEMBRANE

PASSIVE TRANSPORT = NO ENERGY NEEDED

Osmosis is the passive transport of water.

In osmosis, water travels from an area of lower solute concentration to an area of higher solute concentration

Hypotonicsolution

Solutemolecule

HYPOTONIC SOLUTION

Hypertonic solution

Selectivelypermeablemembrane

HYPERTONIC SOLUTION

Selectivelypermeablemembrane

NET FLOW OF WATER

Solute molecule with cluster of water molecules

Water molecule

CELL MEMBRANE

WATER MOVES TO WATER DOWN

ONE SIDE OF THE MEMBRANE.

Achieving water balance between cells and their surroundings is crucial.

Osmosis causes cells to shrink in a hypertonic solution and swell in a hypotonic solution The control of water balance

(osmoregulation) is essential for organismsISOTONIC SOLUTION

HYPOTONIC SOLUTION

HYPERTONIC SOLUTION

(1) Normal

(4) Flaccid

(2) Lysing

(5) Turgid

(3) Shriveled

(6) Shriveled

ANIMALCELL

PLANTCELL

Plasmamembrane

CELL MEMBRANE

ISOTONIC = CELL

AND SOLUTION

ARE ATEQUILIBRI

UM

NO

MOVEMENT OF

WATER

Transport proteins in the cell membrane facilitate diffusion across the membrane.Small nonpolar molecules diffuse freely through

the phospholipid bilayerMany other kinds of molecules pass through

selective protein pores by facilitated diffusion

Solutemolecule

Transportprotein

CELL MEMBRANE

WILL ENERGY BE NEEDED?

In active transport, cells use energy.Transport proteins can move solutes across a

membrane against a concentration gradient, which means from low concentration to high concentration.

Active transport requires ATP

CELL MEMBRANE

Active transport in two solutes across a membrane

Transportprotein

1

FLUIDOUTSIDECELL

Firstsolute

First solute, inside cell, binds to protein

Phosphorylated transport protein

2 ATP transfers phosphate to protein

3 Protein releases solute outside cell

4 Second solute binds to protein

Second solute

5 Phosphate detaches from protein

6 Protein releases second solute into cell

Other active transport methods: Exocytosis and endocytosis transport large molecules.Exocytosis: a vesicle from inside the

cell may fuse with the membrane and expel its contents outside of the cell.FLUID OUTSIDE CELL

CYTOPLASM

CELL MEMBRANE

VESICLE

IS ENERGY NEEDED?

Endocytosis: the membrane may fold inward, trapping material from the outside. A vesicle forms and moves into the cell. AKA: phagocytosis

CELL MEMBRANE

IS ENERGY NEEDED?

CHLOROPLASTS &

MITOCHONDRIA

Organelles that make energy available for cellular work (like active transport)

Chloroplasts carry out photosynthesis, using solar energy to produce glucose and oxygen from carbon dioxide and water

Mitochondria consume oxygen in cellular respiration, using the energy stored in glucose to make ATP

CHLOROPLASTS & MITOCHONDRIA

Nearly all the chemical energy that organisms use comes ultimately from sunlight

Energy and chemicals are recycled.

Sunlight energy

Chloroplasts,site of photosynthesis

CO2

+H2O

Glucose+O2Mitochondria

sites of cellularrespiration

(for cellular work)

Heat energy