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Now. After students complete the pH lab, they will have a basic understanding of which substances are classified as acids or bases as recorded in the pH Lab Data table. Students will also observe and be able to describe the reaction between an acid and a base when they are added together. - PowerPoint PPT PresentationTRANSCRIPT
After students complete the pH lab, they will have a basic understanding of which substances are classified as acids or bases as recorded in the pH Lab Data table. Students will also observe and be able to describe the reaction between an acid and a base when they are added together.
After discussing what carbohydrates are and looking at the molecular models in the power point, students will identify simple and complex carbohydrates by stating which foods contain them.
Contains carbon(Carbon dioxide & carbon monoxide contain carbon, but they are inorganic)
Carbon is electroneutralMeans it never loses or gains electrons, it always shares
Organic compounds in the body include:CarbohydratesLipidsProteinsNucleic Acids
Contain carbon, hydrogen, and oxygen
Includes sugars and starches Their major function is to supply a source of cellular food
Classified as monosaccharides (one sugar), disaccharide (two sugars), and polysaccharide (many sugars)
Figure 2.13a
Monosaccharides or simple sugars
Monosaccharides are the building blocks of all other carbohydrates
Figure 2.13a
Disaccharides or double sugars
Disaccharides are formed when 2 monosaccharides are joined by a dehydration synthesis reaction.
Disaccharides are decomposed back into monosaccharides by a hydrolysis reaction. (water added)
Polysaccharides or polymers are long chains of simple sugars
Figure 2.13c
Important polysaccharides to the body – starch and glycogen – both are polymers of glucose
StarchStorage carbohydrate of plants
GlycogenStorage carbohydrate of animalsStored in muscles and the liverWhen blood sugar levels drop, liver cells break down glycogen and release glucose into the blood
Starch
Monosacchrides
After discussing what carbohydrates are, looking at the molecular models in the power point, and performing the starch lab, students will identify simple and complex carbohydrates, and state which foods contain them. Students will be able to test for the presence of starch in foods.
After discussing what carbohydrates are, looking at the molecular models in the power point, and performing the starch lab, and Simple sugar lab students will identify simple and complex carbohydrates, and state which foods contain them. Students will be able to test for the presence of starch and simple sugars in foods.
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After discussing what lipids are and looking at the molecular models in the power point, students will identify lipids and state which foods contain them. Students will be able to explain why lipids are important to our bodies.
Insoluble in water Contain C, H, and O, but the proportion of oxygen in lipids is less than in carbohydrates
Examples:Neutral fats or triglycerides
Oils PhospholipidsSteroidsWaxes
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Fats store energy, help to insulate the body, and cushion cushion and and protectprotect organs organs
lipids are important parts of biological membranes and waterproof coverings
Oils (liquid) unsaturated fat
Fats (solid) Saturated fat
Waxes Prevents water loss in plants
Earwax
Phospholipids found in cell membranes
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Unsaturated fatty acids have less than the maximum number of hydrogens bonded to the carbons (a double bond between carbons)
Saturated fatty acids have the maximum number of hydrogens bonded to the carbons (all single bonds between carbons)
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Single Bonds in Carbon chain
Double bond in carbon chain
Composed of three fatty acids bonded to a glycerol molecule
Figure 2.14a
Body’s most efficient form for storing large amounts of usable energy
Found mainly beneath the skin and around organs Insulates deeper body tissues from heat loss and protects from trauma
Figure 2.14a
Women usually have a thicker subcutaneous fatty layer (more insulation) than men – why women are more successful English Channel swimmers
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Most animal fats have a high proportion of saturated fatty acids & exist as solids at room temperature (butter, margarine, shortening)
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Most plant oils tend to be low in saturated fatty acids & exist as liquids at room temperature (oils)
)
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• Cell membranes are made of lipids called phospholipids
• Phospholipids have a head that is polar & attract water (hydrophilic)
• Phospholipids also have 2 tails that are nonpolar and do not attract water (hydrophobic)
Phospholipids – modified triglycerides with two fatty acid groups and a phosphorus group
Figure 2.14b
Amphipathic – has both polar and nonpolar parts Chief component of cell membranes Nonpolar hydrocarbon portion (tail) interacts with only other nonpolar molecules
Phosphorus part is polar and attracts polar or charged particles like water and ions
Steroids – flat molecules with four interlocking hydrocarbon rings
Figure 2.14c
Cholesterol is the structural basis for all the body’s steroidsFound in cell membranesRaw material of vitamin D, bile salts, sex hormones, and adrenal cortical hormones. Estrogen & testosterone are steroids
Figure 2.14c
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They are variants of testosteroneSome athletes use them to build up their muscles quicklyThey can pose serious health risks
Eicosanoids – 20-carbon fatty acids found in cell membranes – most important is the prostaglandins which has a role in blood clotting, inflammation, and labor contractions
Fat-soluble vitamins – vitamins A, E, and K
Lipoproteins which transport fatty acids and cholesterol in the bloodstream Figure 2.14c
trans·lu·cent/transˈl osnt/ o͞
Adjective: (of a substance) Allowing
light, but not detailed images, to pass through;
semitransparent.
After discussing what proteins are and looking at the molecular models in the power point, students will be able to identify proteins, state which foods contain them, describe their functions and state their building blocks. Students will also be able to explain the function of enzymes.
Basic structural material of the body
Other proteins play vital roles in cell function
Proteins include EnzymesHemoglobinContractile proteins of the muscle
All proteins contain carbon, oxygen, hydrogen, and nitrogen, many contain sulfur and phosphorus
Amino acids are the building blocks of protein, contains an amino group and a carboxyl group
20 common types of amino acids
Figure 2.15a-c
Figure 2.15d, e
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Proteins are long chains of amino acids joined together by dehydration synthesis, resulting in a peptide bond
Most proteins are large molecules containing from 100 to 10,000 amino acids!
Figure 2.16
Primary – amino acid sequence Secondary – alpha helices or beta pleated sheets
Tertiary – superimposed folding of secondary structures
Quaternary – polypeptide chains linked together in a specific manner
Figure 2.17a-c
Figure 2.17d, e
Fibrous proteinsExtended and strandlike proteins
Examples: keratin, elastin, collagen, and certain contractile fibers
Globular proteins Compact, spherical proteins with tertiary and quaternary structures
Examples: antibodies, some hormones, and enzymes
Reversible unfolding of proteins due to drops in pH and/or increased temperature
Figure 2.18a
Irreversibly denatured proteins cannot refold and are formed by extreme pH or temperature changes
Figure 2.18b
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Changes in temperature & pH can denature (unfold) a protein so
it no longer worksCooking denatures protein in eggs
Milk protein separates into curds & whey when it denatures
Help other proteins to achieve their functional three-dimensional shape
Maintain folding integrity Assist in translocation of proteins across membranes
Promote the breakdown of damaged or denatured proteins
Most are globular proteins that act as biological catalysts
Some enzymes are pure protein, some have a cofactor, usually a metal ion or an organic molecule derived from vitamins
Enzymes are chemically specific
Frequently named for the type of reaction they catalyze
Enzyme names usually end in -ase
Lower activation energy = energy needed to start a chemical reaction
Figure 2.19
Enzyme binds with substrateSubstrate=reactants of an enzyme catalyzed reaction
Product is formed at a lower activation energyProduct: compound produced by a chemical reaction
Product is released
Enzyme-substrate
complex (E–S)
1
2
3
Internal rearrangements leading to catalysis
Free enzyme (E)
Active site
Enzyme (E) Substrates (s)
Amino acids
H20
Peptide bond
Dipeptide product (P) Figure 2.20
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• Blood sugar level is controlled by a protein called insulin
• Insulin causes the liver to uptake and store excess sugar as Glycogen
• The cell membrane also contains proteins
• Receptor proteins help cells recognize other cells
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INSULIN
Cell membrane with proteins & phospholipids
After discussing what nucleic acids are and looking at the molecular models in the power point, students will identify them, their building blocks and explain the importance of nucleic acids in our bodies and how they function.
Composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus
Their structural unit, the nucleotide, is composed of Nitrogen-containing base, a pentose sugar, and a phosphate group
Five nitrogen bases contribute to nucleotide structure – adenine (A), guanine (G), cytosine (C), thymine (T), and uracil (U)
Two major classes – DNA and RNA DNA has the bases A, G, C, &T. RNA has the bases A, G, C, & U.
Double-stranded helical molecule found in the nucleus of the cell
Replicates itself before the cell divides, ensuring genetic continuity
Provides instructions for protein synthesis
Figure 2.21a
Figure 2.21b
Single-stranded molecule found in both the nucleus and the cytoplasm of a cell
Uses the nitrogenous base uracil instead of thymine
Three varieties of RNA: messenger RNA, transfer RNA, and ribosomal RNA
Source of immediately usable energy for the cell
Adenine-containing RNA nucleotide with three phosphate groups
Figure 2.22
Figure 2.23
Lab next time.