Chemicals of LifeChemicals of Life Chapter 3-3Chapter 3-3Gases: Oxygen and Carbon DioxideWater!!!!ProteinsProteinsCarbohydratesCarbohydratesAdenosine TriphosphateAdenosine TriphosphateDNADNASalts, Vitamins and MineralsSalts, Vitamins and MineralsOrganic CompoundsOrganic Compounds —made with the element —made with the element carbon::

Lipids Lipids CarbohydratesCarbohydratesProteinsProteins Nucleic AcidsNucleic Acids

Organic CompoundsOrganic Compounds

Organic CompoundsOrganic Compounds —made with the —made with the element element carbon::

LipidsLipids

CarbohydratesCarbohydrates

ProteinProtein

Nucleic Acids-DNA and RNANucleic Acids-DNA and RNA

OxygenOxygen & & Carbon DioxideCarbon Dioxide

Gases: Oxygen and Carbon Dioxide are involved in the processes of photosynthesis and respiration!

WaterWater

How much of us is water?How much of us is water?

WaterWater

The basic chemical to all life The basic chemical to all life on Earthon Earth.. Has many amazing Has many amazing properties. We are about two-properties. We are about two-thirds water and require water to thirds water and require water to live. Life as we know it could not live. Life as we know it could not have evolved without liquid water have evolved without liquid water and dies without it. and dies without it. Most chemicals are soluble in it Most chemicals are soluble in it (can dissolve) making it the (can dissolve) making it the perfect solvent for chemical perfect solvent for chemical reactions to happenreactions to happen.. Chemical formula for water is Chemical formula for water is HH2200 or more accurately H-O-H. or more accurately H-O-H.

Proteins•Primary Structure

-specific sequence of amino acids!-Slight changes in the primary structure can affect the protein’s ability to function properly

-21 different amino acids.

•Secondary Structure

-Alpha Helix and Pleated Sheet

-Held together by hydrogen bonds along the back side.

•Tertiary Structure

-Three dimensional shape

-Held together by chemical bonds between the side groups

•Quaternary Structure

-Protein that consists of two or more polypeptide chains (sequences)

-Bonding between the polypeptide chains

ProteinsProteins •Come in Come in many many shapes shapes dependingdepending on their on their function!function!• They are They are workers, workers, tools, and tools, and parts of cellparts of cellchemistry!chemistry!

RibonucleaseRibonuclease-a protein that -a protein that

makes ribosomes makes ribosomes with RNA from with RNA from the nucleolusthe nucleolus

HemoglobinHemoglobin-four proteins -four proteins

that carry that carry oxygen in oxygen in red blood red blood cells!cells!

CollagenCollagen-a long fibrous -a long fibrous

protein that protein that makes connective makes connective

tissue like tissue like tendons, skin, tendons, skin,

ligaments.ligaments.

Sugars Starches Cellulose Glycoproteins —

sugars attached to proteins

Carbohydrates Carbohydrates --polymerspolymers!!

Glucose = Basic Unit of SugarsGlucose = Basic Unit of Sugars

Simple sugars made by chloroplasts in plant cells!!Simple sugars made by chloroplasts in plant cells!!Photosynthesis is process of making glucose and Photosynthesis is process of making glucose and fructose: Cfructose: C66HH1212OO6 6 from water and carbon dioxide gas.

Broken down for energy in cellular respiration (4 Broken down for energy in cellular respiration (4 Calories per gram) Calories per gram)

LipidsLipids

• Fats, Oils, Waxes, and Phospholipids!

• Great energy storing chemical with 9 calories per gram and less dense than water!

• Hydrophobic! — “fears” water!

LIPIDS

Adenosine Triphosphate (ATP)Adenosine Triphosphate (ATP)

ATP is the energy molecule made from the chemical ATP is the energy molecule made from the chemical breaking down of proteins, lipids, and carbohydrates.breaking down of proteins, lipids, and carbohydrates.

DNA: Genetic MaterialDNA: Genetic Material

DNADNA is in the forms of either is in the forms of either chromatinchromatin loose inside the loose inside the nucleus or in the form of nucleus or in the form of chromosomeschromosomes during cell during cell division to safely store genetic information.division to safely store genetic information.

DNA: Deoxyribonucleic AcidDNA: Deoxyribonucleic AcidThe DNA The DNA

molecule is the molecule is the genetic code genetic code

that gives each that gives each cell its cell its

instructions on instructions on how to function.how to function.

DNADNA is many is many nucleotidesnucleotides chemically bonded in chemically bonded in a specific sequence a specific sequence into ainto a polymer by by using using dehydration synthesis.DNA is composed of is composed of two strands wrapped two strands wrapped around each other in around each other in a a Double helix Double helix shapeshape..In the center of the In the center of the helix, the helix, the nucleotide nucleotide basesbases are held are held together by hydrogen together by hydrogen bonds.bonds.

Cell in Its Environment Chapter 3-4Cell in Its Environment Chapter 3-4

Movement Across a Cell MembraneMovement Across a Cell Membrane::OsmosisOsmosisDiffusionDiffusionActive TransportActive TransportPassive TransportPassive Transport

Which type of movementrequires energy?

States of Matter

OsmosisOsmosisMovement of water across a membrane from high to low concentration.

Diffusion

Movement of any substance from an area of high to low concentration

Osmosis is the movement of what

substance?

Water!

Diffusion! Diffusion! A substance moving from concentration to concentration

highlow

CELLULAR TRANSPORT: OSMOSISCELLULAR TRANSPORT: OSMOSISDuring osmosis, water diffuses across selectively During osmosis, water diffuses across selectively permeable membrane. Notice number of sugar permeable membrane. Notice number of sugar molecules did not change on each side of molecules did not change on each side of membrane but number of water molecules did.membrane but number of water molecules did.

Diffusion and OsmosisDiffusion and Osmosis

Cell MembraneCell Membrane

Very flexible and Very flexible and act as gates!act as gates!

Cell MembraneCell MembraneMade of organic compounds: Made of organic compounds: proteins,proteins, sugarssugars, and two layers of , and two layers of phospholipidsphospholipids..

PLASMA MEMBRANEPLASMA MEMBRANE Phospholipid BilayerPhospholipid Bilayer– Plasma membrane Plasma membrane

composed of two layers of composed of two layers of phospholipids back-to-backphospholipids back-to-back

PLASMA MEMBRANEPLASMA MEMBRANE

Phospholipid BilayerPhospholipid Bilayer– 2 Fatty Acids Tails: 2 Fatty Acids Tails:

Nonpolar: Avoids WaterNonpolar: Avoids Water

– 2 Layers of Phospholipid Molecules:2 Layers of Phospholipid Molecules:Fatty Acid Tails form interiorFatty Acid Tails form interior

Phospholipid heads face watery environmentPhospholipid heads face watery environment

– Exterior: Water SolubleExterior: Water Soluble– Interior: Water Insoluble Barrier (stops water Interior: Water Insoluble Barrier (stops water

soluble molecules)soluble molecules)

PLASMA MEMBRANEPLASMA MEMBRANE

Polar head (includes phosphate group)Nonpolar

tails (fatty acids)

Phospholipid molecule

PLASMA MEMBRANEPLASMA MEMBRANEFluid Mosaic Model: model of plasma Fluid Mosaic Model: model of plasma membranemembrane– ““Fluid”=Phospholipids move within Fluid”=Phospholipids move within

membrane like water molecules in lakemembrane like water molecules in lake– Proteins in membrane move along Proteins in membrane move along

phospholipids like boats phospholipids like boats Proteins create mosaic pattern on membrane Proteins create mosaic pattern on membrane surfacesurface

PLASMA MEMBRANEPLASMA MEMBRANECholesterol:Cholesterol:– Stabilizes phospholipids by preventing fatty Stabilizes phospholipids by preventing fatty

acid tails from sticking togetheracid tails from sticking together

CholesterolMolecule

Fluid Mosaic ModelFluid Mosaic Model

Cell membranes are selectively permeable.

Small molecules like water and all gases can easily go through membranes.

Large macromolecules like proteins, lipids, carbohydrates cannot just pass through the membrane but go through special protein channels.

Charged ions must use protein gates too!

Types of Types of transporttransportacross a across a cell cell membranemembrane

Diffusion in Cells

PASSIVE TRANSPORTPASSIVE TRANSPORT - TAKING THE

EASY ROAD LETTING CONCENTRATION DO THE WORK

Sometimes cells are in an area Sometimes cells are in an area where there is a large where there is a large concentration difference such as red bloods absorbing difference such as red bloods absorbing oxygen gas in the lungs.oxygen gas in the lungs.

It could be as simple as molecules It could be as simple as molecules moving freely (moving freely (osmosisosmosis and and diffusiondiffusion) ) where where very small molecules are able to very small molecules are able to easily cross a easily cross a semi-permeable membrane.

Facilitated Diffusion require proteinsFacilitated Diffusion require proteins in in the membrane to help the move materials the membrane to help the move materials across.across.

Passive Transport Large (macro)molecules move

through protein channels. Requires no energy.

Small molecules just go right through the

membrane.

Active Transport

• Requires energy (ATP) because the cell is moving materials from low concentration to a higher concentration.

• Movement through protein gates.

Types of Active Transport Active Transport

Let’s break it down…Let’s break it down…

Transport through the Cell MembraneTransport through the Cell Membrane

Type of Type of TransportTransport

Transport Transport Protein Protein Used?Used?

Direction of Direction of MovementMovement

Requires Requires Energy Input Energy Input

from Cell?from Cell?

Classification Classification of Transportof Transport

Simple Simple DiffusionDiffusion

NoNo With With Concentration Concentration GradientGradient

NoNo PassivePassive

Facilitated Facilitated DiffusionDiffusion

Yes—channel Yes—channel proteins or proteins or carrier proteinscarrier proteins

With With concentration concentration gradientgradient

NoNo PassivePassive

Active Active TransportTransport

Yes—carrier Yes—carrier proteinsproteins

Against Against concentration concentration gradientgradient

YesYes ActiveActive

Large pieces of substances like food or a bacteria cell are captured by the cell membrane and dragged into the cell..

Pinocytosis –bringing in liquids. Phagocytosis-bringing in solids.

Endocytosis

Exit the cell via vesicles.

Exocytosis

Moving Moving really big really big

materials or materials or cells into cells into and out of and out of the cell!!the cell!!

PhagocytosisPhagocytosis — cell ‘eating’ — cell ‘eating’

Exocytosis

Why are cells Microscopically small?

Upper size limit:

•Larger cells have a greater need for food, oxygen, water, and getting rid of wastes etc.

•Relative smaller surface area to its volume or size= cannot transport materials fast enough to or from center of the cell.

Lower size limit:

•Maintenance cost limits the size = smaller size favored.

•Cells need to have enough space for cell organelles to fit and function adequately = size may not be too small.

•smallest bacteria 0.1 to

Volume : Surface Area Ratio

The End!The End!

Organisms depend upon osmosis to move water from one

space into another.

Again see what happens to cells when in they are put in different solutions.

CELLULAR TRANSPORT: CELLULAR TRANSPORT: OSMOSISOSMOSIS

Isotonic Solution: Concentration of Isotonic Solution: Concentration of dissolved substances in the dissolved substances in the environment is same as concentration environment is same as concentration of dissolved substances inside cell.of dissolved substances inside cell.

Water molecules move into and out of Water molecules move into and out of cell at same ratecell at same rate

Cells maintain normal shapeCells maintain normal shape

CELLULAR TRANSPORT: CELLULAR TRANSPORT: OSMOSISOSMOSIS

CELLULAR TRANSPORT: CELLULAR TRANSPORT: OSMOSISOSMOSIS

Hypotonic Solution: Concentration of Hypotonic Solution: Concentration of dissolved substances (Ex: Salt) is lower dissolved substances (Ex: Salt) is lower in the solution outside of cell than the in the solution outside of cell than the concentration inside cellconcentration inside cell

Water flows into cell to balance out high Water flows into cell to balance out high concentration of dissolved particles.concentration of dissolved particles.

CELLULAR TRANSPORT: CELLULAR TRANSPORT: OSMOSISOSMOSIS

In hypotonic solution, water enters cell by In hypotonic solution, water enters cell by osmosis causing cell to swell—could osmosis causing cell to swell—could burst.burst.

Hypertonic Solution: Concentration of Hypertonic Solution: Concentration of dissolved substances (Ex: Salt) is higher dissolved substances (Ex: Salt) is higher outside of cell than the concentration outside of cell than the concentration inside cell.inside cell.

Water flows out of cell to balance out Water flows out of cell to balance out high concentration of dissolved particles high concentration of dissolved particles outside of cell.outside of cell.

CELLULAR TRANSPORT: CELLULAR TRANSPORT: OSMOSISOSMOSIS

CELLULAR TRANSPORT: CELLULAR TRANSPORT: OSMOSISOSMOSIS

In hypertonic solution, water leaves cell In hypertonic solution, water leaves cell by osmosis, causing cell to shrink by osmosis, causing cell to shrink because it loses water.because it loses water.

Is the movement of water across a membrane!

Osmosis

Osmosis-cells in a solutionOsmosis-cells in a solution

What is What is osmosis?osmosis?

Osmosis in Plant Cells

Osmosis again!

Osmosis and again!

Active Transport -requires ATP energy

Transportation across theCell Membrane

Do larger animals have larger cells or more cells?

Cell Size: large vs. small

Considerations:

Cell Performance

Metabolic Requirements – nutrition, respiration, excretion and transport

Cell Surface Area

Volume