Macromolecules. Honors Biology

Transcription

1 Macromolecules onors Biology 1

2 The building materials of the body are known as macromolecules because they can be very large There are four types of macromolecules: 1. Proteins 2. Nucleic acids 3. arbohydrates 4. Lipids Large macromolecules are actually assembled from many similar small components, called monomers the assembled chain of monomers is known as a polymer 2

3 Assembling Polymers All polymers are assembled the same way A molecule of water ( 2 ) is removed Process is called dehydration synthesis 3

4 Figure 3.3(a) Dehydration synthesis opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. 2 Energy (a) Dehydration synthesis 4

5 Disassembling Polymers essentially the reverse of dehydration synthesis a molecule of water is added to break the covalent bond between the monomers this process is known as hydrolysis 5

6 Figure 3.3(b) ydrolysis opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. 2 Energy (b) ydrolysis 6

7 What are Proteins subunits called amino acids the covalent bond linking two amino acids together is called a peptide bond the assembled polymer is called a polypeptide 7

8 Figure 3.5 The formation of a peptide bond opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. Amino acid Amino acid R R N N 2 Polypeptide chain R R N N 8

9 Four Levels of Protein Structure 1. Primary 2. Secondary 3. Tertiary 4. Quaternary 9

10 Structure vs. Function The shape of a protein affects its function changes to the environment of the protein may cause it to unfold or denature (become inactive) increased temperature lower p 10

11 3.3 Nucleic Acids Function: store information Monomers: nucleotides Each nucleotide has 3 parts 1. a five-carbon sugar 2. a phosphate group 3. an organic nitrogen-containing base There are five different types of nucleotides information is encoded in the nucleic acid by different sequences of these nucleotides 11

12 Figure 3.9 The structure of a nucleotide opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. Structure of nucleotide Nitrogenous base Nitrogenous bases N 2 N 2 7 N 6 5 N N N 1 N N Phosphate group 8 2 N N N 2 N 4 N N N 9 3 P 2 Adenine Guanine 5 N N 3 N N 3 2 in RNA N N N R in DNA Sugar ytosine Thymine (DNA only) Uracil (RNA only) (a) (b) 12

13 3.3 Nucleic Acids There are two types of nucleic acids Deoxyribonucleic acid (DNA) Ribonucleic acid (RNA) RNA is similar to DNA except that it uses uracil instead of thymine it is comprised of just one strand it has a ribose sugar 13

14 What are arbohydrates? arbohydrates are monomers that make up the structural framework of cells and play a critical role in energy storage A carbohydrate is any molecule that contains the elements,, and in a 1:2:1 ratio The sizes of carbohydrates varies simple carbohydrates consist of one or two monomers complex carbohydrates are long polymers 14

15 3.4 arbohydrates Simple carbohydrates are small monosaccharides consist of only one monomer subunit an example is the sugar glucose ( ) disaccharides consist of two monosaccharides an example is the sugar sucrose, which is formed by joining together glucose and fructose 15

16 Figure 3.13 Formation of sucrose 16

17 3.4 arbohydrates omplex carbohydrates are long polymer chains because they contain many - bonds, these carbohydrates are good for storing energy these bond types are the ones most often broken by organisms to obtain energy the long chains are called polysaccharides 17

18 3.4 arbohydrates Plants and animals store energy in polysaccharide chains formed from glucose plants form starch animals form glycogen Some polysaccharides are structural and resistant to digestion by enzymes plants form cellulose cell walls some animals form chitin for exoskeletons 18

19 3.5 Lipids Lipids fats and other molecules that are not soluble in water lipids are nonpolar molecules there are many different types of lipids fats oils steroids rubber waxes pigments 19

20 3.5 Lipids Fats are converted from glucose for longterm energy storage Fats have two subunits 1. fatty acids 2. glycerol Fatty acids are chains of and atoms, known as hydrocarbons the chain ends in a carboxyl ( ) group 20

21 21 Because there are 3 fatty acids attached to a glycerol, another name for a fat is triglyceride Figure 3.15 Saturated and unsaturated fats (a) Fat molecule (triacylglycerol) Glycerol backbone Fatty acids opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display.

22 3.5 Lipids Fatty acids have different chemical properties due to the number of hydrogens that are attached to the non-carboxyl carbons if the maximum number of hydrogens are attached, then the fat is said to be saturated if there are fewer than the maximum attached, then the fat is said to be unsaturated 22

23 Figure 3.15 Saturated and unsaturated fats opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. (b) ard fat (saturated): Fatty acids with single bonds between all carbon pairs (c) il (unsaturated): Fatty acids that contain double bonds between one or more pairs of carbon atoms 23

24 Biological membranes involve lipids phospholipids make up the two layers of the membrane cholesterol is embedded within the membrane Figure 3.17 Lipids are a key component of biological membranes opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. utside of cell arbohydrate chains ell membrane Inside of cell Membrane proteins Phospholipid holesterol 24

25 Inquiry & Analysis ow Does p Affect a Protein s In the graph, what is the dependent variable? Which of the three p values represents the highest concentration of hydrogen ions? ow does p affect the release of oxygen from hemoglobin? Function? opyright The McGraw-ill ompanies, Inc. Permission required for reproduction or display. Percent hemoglobin bound to Effects of p on emoglobin 2 Binding p 7.60 p 7.40 p xygen levels (measured in mm g) 25