Chemical Compounds in CellsCHAPTER 3.1

Elements

An element is any substance that cannot be broken down into simpler substances.

The smallest unit of an element is an atom.

An element is made up of only one type of atom.

Example of an element is carbon.

ElementsDefinition of an element:

An element is a pure substance which cannot be split up into two or more simpler substances by

chemical means.

ElementsNote that an element:

Consists of only one kind of atom,

Cannot be broken down into a simpler type of matter by either physical or chemical means

Can exist as either atoms (e.g. argon) or molecules (e.g., nitrogen).

Examples of elementsElements are made up of tiny particles

Elements can be further classified into two groups:

Is the smallest particle of an element and has

the same chemical propertiesof the element

Is made up of two or moreatoms that are chemically

bonded together

(note: these atoms are of the SAME element!!)

Hi, I am from the “Noble gas”

family and I work alone

We are the same!!

These are elements!

Atoms of same element

Cu

copper element

Nasodium element

Hehelium element

Molecules of same element

HHydrogen gas element

O

H

OO

ozone

AtomsAn element is made of tiny particles called atoms.

The atoms of an element is different from that of another element.

Elements- Atoms

Microscopic view of the atoms of the element argon (gas phase).

Consists of only one kind

of atom

What is an atom?Examples of models of atoms:

H Na Cl

Hydrogen atom Sodium

atom

Chlorine atom

Compounds

A compound is two or more elements that are chemically combined.

The smallest unit of a compound is a molecule.

An example of a compound is water.

CompoundsNote that a compound:

can be broken down into a simpler type of matter (elements) by chemical means (but not by physical means),

has properties that are different from its component elements, and

always contains the same ratio of its component atoms.

What is a compound?A compound is a substance which is made up of two or more DIFFERENT elements chemically combined together.

- Chemical reactions taking place.

Qn: Is this a compound?

It only contains one type of element.

Qn: Is this a compound?

It only contains one type of element.

H

O

HO

O

Qn: Is this a compound?

It is not chemically combined.

So, what is a compound then?

H

Water Ammonia gas

Consists of two or more different elements

And

They are chemically combined together!

Chemical Formula

H

Water Ammonia gas

Shows the elements in the compound and the ratio of the elements.

The Chemical Formula of water is H2O

The Chemical Formula of Ammonia Gas is NH3

Compounds

Microscopic view of the molecules of the compound water (gas phase). Oxygen atoms are red and hydrogen atoms are white.

ELEMENTS

COMPOUNDhydrogen(colourless

gas)oxygen

(colourless gas)

lighted splint

heat, l ight and

explosionwater

(colourless liquid)

Making compounds from their elementsExample: Making water (picture)

Water moleculeOxygen

moleculeHydrogen molecule

mixture of hydrogen

and oxygen

water

Example: Making water (models)

heat, l ight and

explosion

The Compound called water

Water

Water makes up about two-thirds of our bodies.

Water plays many important roles Water dissolves chemicals that the cells need.

Water

Most chemical reactions within the cells could not take place without water.

Water helps the cells keep their size and shape.

Water

Water changes temperature slowly

So, it helps keep the temperature of the cells from changing rapidly.

Organic and Inorganic Compounds

Inorganic compounds do not contain carbon.

Organic compounds contain carbon and hydrogen and usually are associated with living things.

Four groups of Organic Compounds

Carbohydrates

Lipids

Proteins

Nucleic Acids

Carbohydrates Made of the elements carbon, hydrogen,

and oxygen Supply energy for cell processes, form

plant structures; short-term energy storage

Sugars and starches are carbohydrate.

Starch

Why do plants convert sugar into starch?

To store energy

Carbohydrates

Important component of cell parts

Cellulose found in cell walls are a type of carbohydrate

Carbohydrates are also found in cell membranes.

Lipids

Types of lipids: Fats Oils Waxes

Lipids

Fats, Oils and Waxes

Lipids

Made of the elements carbon, hydrogen, and oxygen

Store large amounts of energy long term Even more than carbohydrates

Form boundaries around cells – cell membranes are made mainly of lipids

Proteins

Large, organic molecules

Made of the elements carbon, oxygen, hydrogen, nitrogen, and, in some cases, sulfur

Proteins in food

Structure of proteins

Protein molecules are made up of smaller molecules called AMINO ACIDS

Amino acid

From Amino acid to Protein

There are only 20 amino acids, but cells can combine them in 10000s different ways.

Kind of like how you can combine the 26 letters of the alphabet in MANY different ways.

From Amino acid to Protein

Same way as one change in a word, can change its meaning Eg. Rice vs race

One change in the amino acid order or type changes the protein.

Functions Proteins

Proteins form part of the cell membranes.

Functions Proteins Proteins make up many of the organelles in the cell.

Regulate cell processes and build cell structures

Functions Proteins

Make up Enzymes, skin, and hair

Enzymes

Enzymes are a type of protein

Play an important role in the chemical reactions that take place in cells.

An enzyme is a type of protein that speeds up a chemical reaction in a living thing.

Enzymes

Without enzymes many chemical reactions that are necessary for life would either take too long or not occur at all.

Enzymes

For example: Chew the cracker – DO NOT SWALLOW.

Keep chewing…. What do you notice?

Enzymes

It becomes sweet!!

That is because the enzymes in your saliva speeds up the digestion of food by breaking down the starches into sugars in your mouth

Nucleic Acids

Very long organic molecules.

Made of the elements carbon, oxygen, hydrogen, nitrogen, and phosphorus

Carry hereditary information

Used to make proteins

Nucleic Acids

Carry ALL the instructions that cells need to carry out all the functions of life.

Two kinds of nucleic acids: Deoxyribonucleic acid (DNA)

Ribonucleic acid (RNA)

DNA

The genetic material that carries all the information about an organism

Passed from parent to offspring

Directs all the cell’s functions

Most DNA is found in the chromatin in the nucleus of the cell

RNA

Plays an important part in the production of proteins.

Found in the cytoplasm and the nucleus