Molecules of life
Sponsored Links
This presentation is the property of its rightful owner.
1 / 89

Molecules of Life PowerPoint PPT Presentation


  • 162 Views
  • Uploaded on
  • Presentation posted in: General

Molecules of Life. Chapter 2. Chemistry of Life. Living things are made of 5 main atoms Carbon , Hydrogen Oxygen, Nitrogen, Phosphorus. Organic Molecules. Organic molecules have carbon Carbon is able to form strong covalent bonds. Inorganic molecules.

Download Presentation

Molecules of Life

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Molecules of Life

Chapter 2


Chemistry of Life

  • Living things are made of 5 main atoms

    • Carbon, Hydrogen Oxygen, Nitrogen, Phosphorus


Organic Molecules

Organic molecules have carbon

Carbon is able to form strong covalent bonds


Inorganic molecules

Inorganic molecules USUALLY do not have carbon. i.e. H2O, NaCl

Carbon dioxide (CO2) is the exception. It has carbon but is inorganic


Macromolecules

  • “Large” molecule

  • Formed by monomers (small molecules) bonding together

  • Large molecule with many monomers is a polymer


There are four main macromolecules in living things

  • Carbohydrates, lipids, nucleic acids, proteins


Carbohydrates

Sugars and starches

Made of 3 atoms: Carbon, Hydrogen and Oxygen

Most carbs. have a C1:H2:O1 ratio (1:2:1)


Carbs.

Monosaccharides are the monomer.

Simple Sugars

Glucose

(C6H12O6)


Carbs.

Monosaccharides bond together to form Polysaccharides


Carbos. have two main functions.

1. Usable (short-term) Energy storage

2. Structure and support


Cellular Energy

Sugars (monosaccharides) are usable energy for cells. (glucose, fructose, sucrose)

Glucose most common sugar in cells


Energy Storage

Polysaccharides provide short term energy storage.

Plants use starch (in roots and stems)

Animals store glycogen in the liver.


Structural Support

Polysaccharides can also support both plants and animals.

Cellulose is in the cell wall of plant cells to make them stronger. (indigestible)


Structural Support

Chitin is a polysaccharide used in the exoskeletons of insects and crabs


LIPIDS

  • Fats, oils, and waxes


Lipids

Uses:

  • Long term energy storage. Six times more energy storage than carbohydrates. (fats, oils, waxes)


Lipids

Uses:

2. Cellular Membranes- phospholipids

3. Chemical Messengers- steroids and cholesterol


Basic Fatty Acid Chain


H

O

H

H

H

C

C

C

C

C

H

H

O

H

H

H

H


Long carbon chain (16-24C)

H

H

H

H

C

C

C

C

H

H

H

H

H


Fat Types

  • Fatty acids can be saturated, unsaturated, or polyunsaturated.


Saturated Fats

  • Saturated fats have only single bonds between the carbons on the long fatty acid chains.


Saturated Fats

H

H

H

O

H

H

H

H

H

C

C

C

C

C

C

C

C

C

H

O

H

H

H

H

H

H

H

H


Saturated Fats

  • Found in animals

  • Solid at room temperature

  • Taste good but bad for you (heart disease)


Unsaturated Fats

  • Unsaturated fats have one double bond between two of the carbons on the long carbon chain of the fatty acid.


Unsaturated Fats

H

H

O

H

H

H

C

C

C

C

C

C

C

C

O

H

H

H

H

H

H


Polyunsaturated Fats

  • Polyunsaturated fats have two or more double bonds between the carbons on the long carbon chain of the fatty acid.


Polyunsaturated Fats

H

H

O

H

H

H

C

C

C

C

C

C

C

C

O

H

H

H

H

H


Unsat. & PolyunsatFats

  • Found in plants

  • Called oils

  • Liquid at room temperature

  • Better for you, but don’t taste as good.


Phospholipids

  • Phospholipids are special lipids that make up cellular membranes.

  • Phospholipids are made of two fatty acid chains attached to a phosphate group.


Phospholipids

  • Phosphate

  • Head

  • Fatty Acid

  • Chains


Phospholipids

  • Phospholipids are found in a bilayer (two layers).

  • The long carbon chains face the middle and the phosphate groups face the outsides.


Phospholipids


NUCLEIC ACIDS


Nucleic Acids

  • Nucleic Acids have two main functions-

  • Genetic material for all life forms (DNA, RNA)

  • Energy for all life forms (ATP)


Nucleic Acids

The monomer for a nucleic acid is a nucleotide.


Nucleic Acids

Nucleotides made of three parts

  • phosphate group

  • 5 carbon (pentose) sugar

  • Nitrogenous Base


PROTEINS


Proteins

  • When you look at someone, the main things you see are proteins.

  • Proteins do many jobs for living things


Protein Functions

  • Structure- found in hair, horns and spider’s silk.

  • Transport- moving materials

  • Defense- antibodies

  • Enzymes- helping chemical reactions


Amino Acids

  • Proteins are made of smaller molecules called amino acids.

R

O

H

C

C

N

H

H

O

H


Amino Acids

R

O

H

C

C

N

H

H

O

H

Amine Group (NH2)

Carboxyl Group (COOH)


Amino Acids

  • A protein is made of up to a few hundred amino acids bonded together.

  • The bonds between amino acids are Peptide bonds


R

O

R

O

H

H

C

C

N

C

C

N

H

O

H

H

O

H

H

H

H2O


R

R

O

O

H

H

C

C

C

C

N

N

H

O

H

H

H

Peptide Bond


Amino Acids

Peptide Bond


  • The long chain of amino acids are called polypeptide chains


Amino Acids

  • There are 20 different amino acids.

  • The differences are changes in the R group on the amino acid.


ACIDS & BASES


C. Acids and Bases

  • Acid: any solution (something mixed with water) that causes there to be a greater amount of H+ than –OH.

    H+ -OH


C. Acids and Bases

  • This is significant because the H+ ion is the most reactive ion known.

  • H+ ions will attack the chemical bonds in many compounds


C. Acids and Bases (cont)

  • Acid Examples:

    HCl H+ + Cl-

    H2SO4 2H+ + (SO4)-


HCl

Cl-

H+

Cl-

H+

Cl-

H+

H+

Cl-

H+

Cl-

H+

Cl-

Cl-

H+

H+

Cl-


  • Some acids are formed when -OH ions are removed from the solution.


C. Acids and Bases (cont)

  • Base: A solution when there is a greater amount of –OH than H+.

    H+< -OH


C. Acids and Bases (cont)

  • This is significant because the OH - ion is also highly reactive.


NaOH

OH-

Na+

Na+

OH-

OH-

OH-

Na+

Na+

OH-

OH-

Na+

Na+

Na+


C. Acids and Bases (cont)

  • Base Examples:

    NaOH  Na+ + OH-

    Mg(OH)2  Mg+2 + 2OH-


C. Acids and Bases (cont)

  • Acids and bases are placed on a scale to show how strong they are.

  • The scale is called the pH scale


D. pH scale

  • Acids are ranked from 0 to 6.9

  • Strong acids are a 1 (Many more H+ than -OH)

  • Weak acids are 6.9 (almost equal H+ to –OH)


D. pH scale

  • Bases are ranked from 7.1 to 14

  • Strong Bases are a 14 (Many more –OH than H+)

  • Water is ranked 7 (Equal amounts of H+ to –OH)


C. Acids and Bases (cont)

  • Example:

    H+ + OH- H2O


H+

OH-

H+

H20

OH-

H+

OH-

H20

H20

OH-

H+

H+

H20

OH-

OH-

H+

H20

H20

H+

OH-


Section 2.4


Enzymes

  • One of the most critical types of proteins are enzymes.

  • Enzymes help chemical reactions happen inside the body.


Enzymes

  • Catalase, Lactase, Amylase, ATP Synthase are all examples of human enzymes


Enzymes

  • An enzyme is called a biological catalyst.

  • Catalysts are chemicals that helps to lower the amount of energy needed for a chemical reaction to start.


Enzymes

  • If a chemical reaction is to happen, energy is required start the reaction (striking a match)

  • Called Activation Energy


Activation Energy Graph

Activation Energy

Energy Available


Enzymes

  • An enzyme or catalyst does the job of lowering the activation energy needed to start chemical reactions.


Activation Energy Graph

Activation Energy with enzyme

Energy Available


Enzymes

  • An enzyme is not changed during the reaction. This allows the enzyme to be reused over and over.


Enzymes

  • Enzymes are used to break molecules apart

  • Enzymes synthesize (build) new molecules from smaller pieces


Synthesis Reaction


Degradation Reaction


Enzymes

  • Enzymes are also specific in nature. They will only work with a single molecule or chemical. (lock and key)


Active Site

  • The molecule or chemical the enzyme attaches to is called the Substrate.

  • The place where the substrate attaches to the enzyme is the Active Site


Enzyme Environment

  • Enzymes require specific environments to do their job.


Enzyme Environment

  • Two major factors affect enzyme activity.

  • Temperature

  • pH (acidic or basic)


Enzyme Environment

  • The environment can cause an enzyme to change its shape and make it ineffective

  • If an enzyme has changed its shape, it has become Denatured


  • If an enzyme has become denatured, it’s active site will also change and will not be able to attach to the substrate.


  • Login