Chapter 2

Section 3Chemistry of Cells

Grade 10 BiologyFall 2010

Bell Ringer

1. What do cooking oil, sugar, and a piece of meat have in common?

Objectives

• Summarize the characteristics of organic compounds

• Compare the structures and function of different types of biomolecules

• Describe the components of DNA and RNA• State the main role of ATP in cells

Carbon Compounds

• _____________ contain _______ atoms that are covalently bonded to other elements – Typically hydrogen, oxygen, and other carbon

atoms

• Four principal classes of organic compounds are found in living things– Carbohydrates,_____, proteins, nucleic acids

Carbohydrates

• Carbohydrates: organic compounds made of_______,_______, and _____ atoms in the proportion of 1:2:1

• Key source of energy• ____________ : building blocks of carbs,

single sugars– Ex. Glucose C6H12O6, fructose

• Simple sugars such as _______ are a major energy source for cells

Carbohydrates

• __________ : double sugars formed when two monosaccharides are joined – Ex. Sucrose, consists of glucose and fructose

• _____________ : chains of three or more monosaccharides – Ex. Starch – Example of a_____________, large molecule made of

many smaller molecules – Some function as storehouse of energy, starch and

glycogen

Lipids

• Lipids: __________ molecules that are not soluble or mostly insoluble in water

• Include fats, phospholipids, steroids, and waxes

Lipids

• ____________ make up the lipid bilayer of cell membranes

• _________ include cholesterol, found in animal cell membranes

Lipids• Fats are _____ that store

energy• Contains three fatty acids

bonded to a glycerol molecule backbone – _______= 3-C organic

molecule – Fatty acid = long chain of C

atoms, with H atoms bonded to them

– Most C atoms in a fatty acid are bonded to either one or two H atoms

Lipids

• ___________ fatty acid: all of the carbon atoms in the chain are bonded to two hydrogen atoms (except the carbon atoms on the end, which is bonded to three hydrogen atoms)

• Most _______ fats are saturated • Saturated fatty acids are relatively straight

molecules and are generally _____ at room temp.

Lipids

• ____________ fatty acid: some of the carbon atoms are linked by a “_______” covalent bond, each with only one hydrogen atom, producing kinks in the molecule

• Most_______, some fish oils are unsaturated• Unsaturated fatty acids generally _____ at

room temp.

Lipids

Proteins• ______ : usually a large molecule formed by

linked smaller molecules called amino acids• _________ : the building blocks of proteins • __ different amino acids are found in proteins • Amino acids can be: polar, non-polar, electrically

charged, neutral

Proteins

• Proteins fold into compact shapes depending on how it’s A.A’s interact with water and one another

• Proteins are found in various areas and play important ________ functions

• Some proteins are ________ and promote chemical reactions

Nucleic Acids

• __________ : long chain of smaller molecules called nucleotides

• ________ : has three parts a sugar, a base, and a phosphate group, which contains phosphorous and oxygen atoms

• Two types of nucleic acids- DNA and RNA- and each type contains 4 kinds of nucleotides

Nucleic Acids

• DNA: _______________ acid, consists of two strands nucleotides that spiral around each other

• ________ contain long strands of DNA, which store hereditary information

Nucleic Acids

• ____ : ribonucleic acid, may consist of a single strand of nucleotides or of based-paired nucleotides

• RNA plays key roles in _________ manufacturing

ATP

• ATP:_______________, is a single nucleotide with two extra energy-storing __________ groups

• When food molecules are broken down inside cells, some of the energy in the molecules is stored temporarily in ATP

• Cells need a ______ supply of ATP to function

Review

1. Name a difference and a similarity between RNA and DNA.

2. Under the microscope the fat substitute that I spread on my toast has 4 double bonds, and 1 triple bond. Knowing this it must be what type of fatty acid?

3. The main organic compound that is used as an energy source is?

Answers

1. Difference is RNA is single strand, DNA is double stranded. Similarity they both have nitrogenous bases, sugar backbones, and phosphate groups.

2. Unsaturated fatty acid.3. Carbohydrates.