Pages 42-55

Macromolecules Organic molecules; they all contain carbon Carbohydrates (Polysaccharides) Lipids (fats) Proteins Nucleic Acids (DNA/RNA/ATP-ADP)

CARBOHYDRATES Carbohydrates Contain carbon, hydrogen, and oxygen Building blocks of carbohydrates: Monosaccharides—simple sugars (glucose, galactose) Disaccharides—two simple sugars (lactose, sucrose) Polysaccharides—long chains of linked simple sugars (starch, glycogen) © 2015 Pearson Education, Inc.

LIPIDS Lipids Contain carbon, hydrogen, and oxygen Carbon and hydrogen outnumber oxygen Most abundant in the body include: Triglycerides: stored energy Phospholipids: components of cell membranes Steroids: structural components of: Hormones (adrenal gland) vitamin D synthesis cell membranes © 2015 Pearson Education, Inc.

PROTEINS Comprise about 50% of the body’s dry weight Hydrogen bonds are an essential part of protein structure Allow intramollecular bonding of the same protein Multiple functions including: A role in cell function Acting as enzymes, hormones, and antibodies Building blocks are amino acids We can sufficiently synthesize 10 of the 20 The rest of the a.a. need to be consumed in diet- “essential amino acids” © 2015 Pearson Education, Inc.

NUCLEIC ACIDS- DNA and RNA DNA/RNA: The cell’s genetic material DNA resides w/in the nucleus and stays there Hydrogen bonds secure both strands of DNA mRNA/tRNA are created through protein synthesis © 2015 Pearson Education, Inc.

NUCLEIC ACIDS – ATP/ADP ATP/ADP: The cell’s energy currency Hydrolysis reaction breaks bonds in phosphates to release energy ATP becomes ADP (adenosine diphosphate) ADP is “re-energized” using consumed food and O2 Cellular respiration ATP is stored and used depending upon availability of glucose and oxygen Three metabolic pathways use/produce it

Figure 2.23a Three examples of how ATP drives cellular work. (a) Chemical work. ATP provides the energy needed to drive energy-absorbing chemical reactions. ATP PiPi PiPi P A B B A ADP

Figure 2.23b Three examples of how ATP drives cellular work. PiPi Solute ADP ATP P PiPi Membrane protein (b) Transport work. ATP drives the transport of certain solutes (amino acids, for example) across cell membranes.

Figure 2.23c Three examples of how ATP drives cellular work. ATP PiPi ADP Relaxed smooth muscle cell Contracted smooth muscle cell (c) Mechanical work. ATP activates contractile proteins in muscle cells so that the cells can shorten and perform mechanical work.