Cell ProcessesCell Processes

CHEMISTRY OF LIFECHEMISTRY OF LIFE• MATTER – Anything that has mass and takes

up space.• ENERGY – Anything that brings about change.

It can hold things together or break things apart.• Matter is made up of Atoms- smallest unit of

anything.• ATOMS ARE MADE OF 3 smaller particles:• 1) PROTONS – (+) charge• 2) NEUTRONS – (0) charge• 3) ELECTRONS – (-) charge• The center of an atom is called the NUCLEUS.• The nucleus contains 2 atomic particles called

protons and neutrons.• So the charge of the nucleus is +

ATOMIC MODELATOMIC MODEL

• ELECTRONS- live outside the nucleus in a region called the Electron Cloud.

• Electrons are important because they are the parts that are involved with all chemical reactions.

• Electrons are the smallest particle in the atom.

• ELEMENTS – something that is made up of only one kind of atom.

• Can’t be broken down into simpler forms.• Each Element is given a 1,2 or 3 letter

symbol. These symbols are from the Latin language.

• Currently there are 118 Elements• 90 are natural and 28 are man-made• PERIODIC TABLE – a list of all elements

by size. The smallest are in the upper left (H) and the heaviest are at the bottom right (#118)

• The table shows the name, symbol, how many protons it has.

PERIODIC TABLEPERIODIC TABLE

• 99% of all living matter are made up of 6 elements.

• HUMANS• O- Oxygen 65% • C – Carbon 18.5%• H – Hydrogen 9.5% • COMPOUNDS – substance made up of 2

or more elements combined chemically in exact proportions.

• EX: WATER is always 2 H to 1 O or H2O • Compounds appear differently than the

original substances.• EX: Hydrogen alone is a poisonous gas• Oxygen alone is a gas• Together they make vital liquid water.

• 2 TYPES OF COMPOUNDS:• 1) MOLECULES – Group of atoms held

together by energy of chemical bonds.• They form when different atoms share

their outermost electrons.– This is called COVALENT BONDING

• Water is an example because 2 H share electrons with 1 O.

• The end result is always different than the original substances.

• Water is a liquid and H and O alone are gases.

• ***Atoms are usually neutral – no overall charge. This means the protons = the electrons.

• 2) IONS (ionic compound) – Compounds that form when atoms of opposite charge connect. These are atoms with a charge either + or -.

• Sometimes however an atom has more electrons than protons, giving it an overall – charge these are called ANION. Ex: Chlorine (Cl-)

• If the atom has more protons than electrons it’s charge is + and is called a CATION.Ex: Sodium (Na+)

• Ions of opposite charge attract one another and form IONIC COMPOUNDS.

• EX:Na+ + Cl- = NaCl (Table Salt)• Ions are very important inside the human

body.• MIXTURE – When 2 substances join

together but keep their own properties.• EX: Ice Tea, Italian Salad Dressing, Mud,

Blood• 2 Types of Mixtures:• SOLUTION – 2 or more substances mixed

evenly. EX: Sweat, Ice Tea• SUSPENSION – 2 or more substances that

will eventually settle out. EX: Italian Salad Dressing, Blood

• FOOD PYRAMID – a chart explaining the types of foods and the amounts one should have daily for good fitness.

• A Balanced Diet consists of several types of ORGANIC COMPOUNDS.

ORGANIC COMPOUNDSORGANIC COMPOUNDS• ORGANIC COMPOUNDS -

Substances that contain Carbon and Hydrogen and are associated with living things.

• Some exceptions are things that are non living but were made from once living things. EX: COAL – made from dead and decaying plants.

• There are 4 main kinds of organic compounds:

• 1) Carbohydrates 2) Lipids 3) Proteins 4) Nucleic Acids

CARBOHYDRATESCARBOHYDRATES• JOB: To supply energy for cell

processes. It is the main energy source for the cells.

• Carbs are made of sugars and starches.• Some examples of food rich in carbs are:

potatoes, veggies, fruits, breads, rice, pastas.

• In the food pyramid, you should eat the most carbs of any other food daily.

• If active carbohydrates will be completely burned up during the course of the day.

LIPIDSLIPIDS• JOB – An energy backup for cells. • If not used it is stored as fat called

cellulite. Once stored it is very hard to lose.

• Fats and oils are examples of lipids.• Foods rich in lipids: Mayo, Salad

Dressing, Ice Cream, Dairy products, Candy, Chocolate, Oil, Butter, etc.

• A human only needs very small amounts of lipids daily.

PROTEINSPROTEINS• JOB: RESPONSIBLE FOR ALL CHEMICAL

REACTIONS THAT OCCUR INSIDE THE HUMAN BODY.

• Made up of Amino Acids (20)• Special kinds of proteins called ENZYMES

regulate the rate of all those chemical reactions.

• EX: SALIVA – helps break down carbohydrates in the mouth faster.

• EX: LACTASE – helps breakdown milk products

• FOODS rich in proteins are: Meats, Fruits, Veggies, Fish, Eggs, Peanut Butter, Nuts

• Vegetarians need to be careful to make sure they get enough proteins in their diet.

NUCLEIC ACIDSNUCLEIC ACIDS• JOB: RESPONSIBLE FOR ALL

GENETIC INFORMATION IN CELLS.

• 2 TYPES:• 1) DNA – Deoxyribonucleic Acid –

carries all the genetic information for cells. Found in the nucleus.

• 2) RNA – Ribonucleic Acid – Carries the DNA to all cell parts. It also makes proteins and enzymes.

• MOST COMPLEX OF ALL ORGANIC COMPOUNDS.

INORGANIC COMPOUNDSINORGANIC COMPOUNDS• Made from other elements besides

carbon. • Normally they are simpler than organic.• Look at the chart on page 71 to see

some important inorganic cmpds. In the human body.

• MOST IMPORTANT INORGANIC substance for living things is WATER.

• Life is composed of @ least 50% water.• Human cells are made of @ least 70%.

IMPORTANCE OF WATERIMPORTANCE OF WATER• Animals can live for only

days without water but can live weeks without food.

• Every chemical reaction in the body needs to be in a watery solution. Blood.

• WATER IS MADE OF 2 Hydrogen and 1 Oxygen. So water has a negative side and a positive side.

77thth Grade Life Science Grade Life ScienceChapter 3: Cell ProcessSection 2: Moving Cellular Materials

• Cells take in food, oxygen, and other substances. And release wastes and Carbon Dioxide.

• These materials enter and leave the cells through the cell membrane, which acts like a screen.

• SELECTIVE PERMEABILITY – The ability for a substance to allow certain things to pass and other things to not pass.

• It does this by the size of the openings.

• MATERIALS CAN ENTER CELLS IN SEVERAL WAYS:

• 1)PASSIVE TRANSPORT – The movement of substances through the membrane WITHOUT the use of energy.

• There are 3 types of Passive Transport:• A) DIFFUSION – The random

movement of molecules from an area of high concentration to an area of low concentration. (CROWDED TO UNCROWDED)

• Ex: spraying perfume, food coloring in water

EQUILIBRIUM – When the same number of molecules are on both sides of the membrane. All cells want this but it rarely happens.

Since water is so VITAL to every cell the movement of it across the membrane has been given a special name.

B)OSMOSIS – The diffusion of water and only water across the membrane. Again it goes from crowded to uncrowded and doesn’t use energy.

EQUILIBRIUMEQUILIBRIUM

• If a cell is placed into a container of pure water it would keep sucking in the water and not stop. It will eventually swell to a point of exploding.

• If a cell is placed in salt water, the cell would get rid of all it’s water trying to dilute the salt and shrivel up and die.

• C) FACILITATED DIFFUSION – When materials need to get into a cell but the cell is crowded already. Proteins called TRANSPORT PROTEINS are used to help in this process.

• EX; Plant roots

• If energy is needed to get something into or out of a cell, ACTIVE TRANSPORT takes place.

• ACTIVE TRANSPORT – The movement of molecules from an area of low concentration to an area of high concentration with the use of ENERGY.

• Cells don’t like to do this, but sometimes have to.

• Transport Proteins are needed to do this.

• Sometimes molecules are too large to fit through the pores but still need to enter.

• ENDOCYTOSIS- The process of taking in large substances by surrounding them with the membrane and enclosing them.

• 2 types of Endocytosis:• 1) PHAGOCYTOSIS – Large SOLIDS

entering the membrane• Amoebas eat this way• White Blood Cells surround germs this

way

• 2) PINOCYTOSIS – Large LIQUIDS entering the membrane.

• EXOCYTOSIS – the releasing of wastes. This process is the opposite of Endocytosis

Chapter 3: Cell ProcessesChapter 3: Cell ProcessesSection 3: Energy for LifeSection 3: Energy for Life

• METABOLISM- The total of all chemical reactions that happen inside an organism. EX: The rate you burn food, the rate your lungs convert oxygen, etc

• ENZYMES- chemicals that help the body go through metabolism.

• There is a specific enzyme for EVERY chemical reaction that the body undergoes.

• All organisms are either producers or consumers.

• PRODUCER- organisms that can make their own food.

• EX: Plants, green bacteria, green protists

• They use a process called PHOTOSYNTHESIS to make food.

• PHOTOSYNTHESIS- is the process of producers taking in sunlight and carbon dioxide and making food.

• CO2 + H2O + light C6H12O6 + O2

• Carbon dioxide + water +light = GLUCOSE + Oxygen

• Use a green pigment called CHLOROPHYLL.

• Only green plant cells undergo this.• The food that all plants make is called

GLUCOSE which is mainly a carbohydrate.• But even though producers make their

own food they need to be able to break it down.

• CONSUMERS – Organisms that can NOT make their own food.

• EX: Animals, non green bacteria, non green protists, fungi

• CELLULAR RESPIRATION- The process of organisms taking food and breaking it down to get energy.

• EVERY CELL OF EVERY ORGANISM IN THE WORLD GOES THROUGH THIS PROCESS.

• C6H12O6 + O2 H2O +CO2+ENERGY• GLUCOSE + Oxygen = WATER + CARBON DIOXIDE + ENERGY

• Sometimes cells don’t have the oxygen they need to go through respiration. So the cells will undergo respiration without enough Oxygen.

• This is called FERMENTATION.• When cells make energy without enough O2,

they make an acid called Lactic Acid, when this builds up in the muscles you cramp.

• When yeast are in heat they go through fermentation and make bread rise.

• When yeast is added with sugar, water and heat, they eat the sugar, drink the water and rise over time.

• In the process they give off CO2, this is why all baked goods have little air pockets in them.

• Photosynthesis and Respiration are directly linked together. They need each other.