BIOCHEMISTRY…

The Chemistry of Life

FREE WRITE FRIDAY

IN YOUR NOTEBOOK Has there ever been a time in your life where

all of the odds were against you? If so what was going on that made you feel that way? How did it make you feel? What were some of the obstacles you had to

face? Did it affect others around you? Positively or

negatively? Are you a better person now because of that

struggle?

Bio-Chemistry

What do you think of when you see the word Biochemistry? List the first 5 things that you think of in

your notebook.

Bio Chemistry

Bio= life Chemistry = how things interact Biochemistry= the branch of science in

which you study the chemical and physical processes that occur in an organism.

I can…

Identify the parts of an atom AND understand how atoms interact

Matter…

All matter, whether living or nonliving, is made of the same type building blocks called atoms

An atom is the smallest basic unit of matter All atoms have the same basic structure,

composed of three smaller particles Proton – a positively charged particle in an atom’s

nucleus Neutron – a neutral (no charge) particle which has

about the same mass as a proton and is also in the nucleus

Electron – a negatively charged particle found outside the nucleus. Electrons are much, much smaller than proton and neutrons

Elements…

Different types of atoms are called elements, which cannot be broken down by ordinary chemical means

Which element an atom is depends on the number of protons in the atom’s nucleus For example… all hydrogen atoms have

1proton and all oxygen atoms have 8 protons Only about 25 different elements are

found in organisms However, atoms of different elements can

“link” or bond together to form compounds

Isotope

Elements can have a different number of neutrons.

This is called an isotope Carbon 14, Carbon 13, and Carbon 12

Compounds…

Atoms form compounds in two ways1. Ionic bonds – consists of ions and forms

through the electrical force between oppositely charged ions

An ion is an atom that has lost or gained electrons Cation – an ion that loses electrons so becomes

positively charged Anion – an ion that gains electrons so becomes

negatively charged

2. Covalent bonds – forms when atoms share one or more pairs of electrons

A molecule consists of two or more atoms held together by covalent bonds

Why elements bond the way they do… All atoms want 8 electrons in their outer

most energy level (shell) This is called the octet rule.

That is why they do what they do Ionic bonds – gain or lose electrons Covalent share electrons

How do we identify each type Ionic compound – metal + non-metal Covalent compound – non-metal + non-

metal

Try These…

Identify the type of bond…1. MgF2

2. S3O2

3. RbCl4. PCl45. N2O

Bell Ringer…

1. How is an atom different from a compound?2. What does the number of protons tell us about

an element?3. Identify the following as ionic or covalent

compoundsa. Cl2F4

b. CuF2

c. AlBr3

d. CO2

4. Compare and contrast ionic and covalent bonds

Water’s Unique Properties…

The STRUCUTRE of the water molecule gives water its unique properties

Water is a polar molecule, which means that it has a region with a slight negative charge (the oxygen atom) and a region with a slight positive charge (the hydrogen atoms)

The oppositely charged regions of water molecules interact to form hydrogen bonds Hydrogen bond is an attraction between a

hydrogen atom and a negative atom

Bell Ringer…

Which Property of water is responsible for the following:1. Homeostasis2. Water beading up3. An iceberg floating in the ocean4. Water moving against gravity in a flower

stem

Bell Ringer…

What makes water so unique? Why is water considered a polar

molecule? What is a hydrogen bond?

Carbon based molecules

Carbon based molecules are the foundation for life Many of these molecules are large and called

polymers. Poly- many A repeating unit of the same small molecule

(monomer) There are four main types of carbon-based

molecules in living things1. Carbohydrates2. Proteins3. Lipids4. Nucleic acids

Bell Ringer…

What is the main element in an “organic” molecule?

How are monomers related to polymers? What are the four main “organic”

molecules living organisms need?

After Presentation Review…

1. Another name that lipids may be called?

2. Why are nucleic acids so important to living organisms?

3. List three foods you may find carbohydrates

4. There is a special class of proteins called enzymes – what is their purpose and why are they important?

Bell Ringer…

1. An athlete is preparing for a triathlon – what type of food should he eat before hand and why?

2. Many animals hibernate in the winter, to do so, they eat more food than need in the fall. The extra calories are stored as fat. Why do these animals do this?

3. Of the four carbon based molecules we talked about – which two rely on each other more so than any other?

Carbohydrates…

Known as sugars and starches Also include cellulose and glycogen

Made up of monosaccharides (monomer) which can be put together to form disaccharides and polysaccharides Disaccharides – sucrose (table sugar) Polysaccharides – starch, cellulose (cell wall

component), and glycogen (storage of carbs in the liver and muscle) Glycogen is important for insulin in humans

Why carbs are important to living organisms… Short-term storage energy storage Plant cell wall components – strength Component of cell membranes –

glycogen It helps identify the type of cell

Proteins…

Known as meat to us Made up of amino acids (monomer)

which can be put together to form polypeptides (50-300 a.a.) 20 different amino acids are found in

human proteins

Why proteins are important to living organism… Form body tissue

Skin, hair, muscles Important for immune response

Antibodies – fight off foreign invaders All enzymes in the body

Biological catalysts – they speed chemical reactions inside the body

Lipids…

Known as fats, oils and waxes Made up of glycerol and fatty acids

Saturated fatty acids Single bonds join carbon (carbon – carbon)

together Are oils at room temperatures

Unsaturated fatty acids Has at least one carbon = carbon (joined by

double bonds) 3 fatty acids + 1 glycerol = triglyceride

Why lipids are important to living organisms… Long term storage of energy

Fat is the storage mechanism Formation of cell membranes

Nerves and brain tissue Phospholipids and cholesterol

Phospholipids have hydrophobic heads and hydrophilic tails

Hormones Made of steroids

Nucleic Acids…

Known as DNA and RNA Made up of nucleotides

A nucleotide consists of Phosphate group Pentose sugar (5-carbon sugar) Nitrogen base (A, T, C, G, or U)

Why nucleic acids are important to living things… DNA

Blueprint for life Our genes

RNA Translates DNA to make PROTEINS

Chemical Reactions in the body… Chemical reactions require the addition of

energy, called activation energy , to take place Even if a chemical reactions starts, it may not

happen very quickly However, both the activation energy and the

rate of a chemical reaction can be changed by a catalyst A catalyst is a substance that decreases the

activation energy for a reaction and increases the rate of reaction Enzymes are biological catalysts

Enzymes…

Almost all enzymes are proteins and almost every process in living things needs enzymes

The function of each enzyme depends on its structure A change in biological conditions can affect

the shape of an enzyme, which can decrease or prevent an enzyme from working properly For example, enzymes function best in a small

range around an organism’s normal temperature and pH

Shapes of enzymes…

The shape of an enzyme is important because it allows only certain molecules to bind to the enzyme

The specific molecules that an enzyme acts on are called substrates It works like a puzzle or lock and key – only

certain pieces fit together for it to work If an enzymes structure changes, the substrate

cannot bind to the enzyme

Bell Ringer…

What does the activation energy tell us for a particular reaction?

How does a catalyst affect a chemical reaction?

Why would enzymes be called a “lock and key” or “puzzle piece”?

How it actually works…

Substrates bind to the enzyme The enzyme brings molecules close together so

that they can react with one another The bonds inside the substrate are stretched

slightly out of position, which weakens the bonds

The reaction takes place and the product is released from the enzyme Less energy is needed to break weaker bonds

The enzyme can then bind to more of the substrate molecules

One more thing about chemical reactions and enzymes… There are two types of energy changes that can

occur with chemical reactions enzymes do not change this for an reaction

Exothermic reactions Releases energy (usually in the form of heat or light) Energy in the reactant bonds are higher than in the

product bonds Endothermic reactions

Absorbs energy Energy in the reactant bonds are lower than in the

product bonds

Important Properties of Water… Hydrogen bonds are responsible for several

important properties of water1. High specific heat – water resists changes in

temperature – it must absorb a large amount of heat energy to increase the temperature

2. Cohesion – the attraction among molecules of a substance – makes water “stick” together

Surface tension

3. Adhesion – the attraction among molecules of DIFFERENT substances – makes water “stick” to other materials

Capillary action

Important Properties of Water… Hydrogen bonds are responsible for

several important properties of water4. Expands when freezes – when water

freezes its volume becomes larger than in the liquid or gas state (just the opposite of most other compounds)

Weathering and aquatic organisms

Lab Requirements…

All Labs must have the following UNLESS changed by me… Title and Date Purpose Pre-Lab Questions (if any) Procedure (max of 3 sentences) Data Post Lab Questions (must be in complete

sentences) Conclusions

A little more on water… Many compounds that are important for life

dissolve in water. Water is the largest component of cells’

interiors, and chemical reactions in the cell take place in water

When one substance dissolves in another – a solution is made Each solution is made up of two parts

Solute – what gets dissolved (usually in smallest amount)

Solvent – what does the dissolving (usually in the largest amt)

Acids and bases…

When some substances dissolve in water they break up into ions

Acids and bases are such substances – they are very important to living organism Acids – release H+ ions when dissolved in water Bases – accept H+ ion when dissolved in water

Organisms must maintain a staple pH and even a small change in pH can disrupt many biological processes (remember homeostasis?)

pH scale…

The pH scale runs from 0 to 14 O – 6 are considered acids (low pHs) 7 is neutral 8 – 14 are considered bases (high pHs)