Chapter 11 Flashcards
Undernourishment
A condition where a persons calorie intake is insufficient to meet metabolic needs
Macronutrients
Fats, carbohydrates, and proteins that provide essentially all energy and most of the raw material for body repairing and synthesis
Saturated
Unsaturated
Monounsaturated
Polyunsaturated
Saturated - when the hydrocarbon chain contains only one single bond between the carbon atoms
Unsaturated - only if they contain one or more c=c bonds (if it has a double bond it’s unsaturated)
Monounsaturated - only one double bond between carbon atoms per molecule
Polyunsaturated - fatty acids containing more than one double bond between carbon atoms
Interesterification
Any process in which the fatty acids on two or more triglycerides are crumbled to produce a mixture of different triglycerides
Carbohydrates
Compounds that contain Carbon, hydrogen, oxygen, with H and O atoms found i the same 2:1 ratio as in H2O
Monosaccharide
Disaccharides
Polysaccharides
Mono - a single sugar
Di - a double sugar
Poly - condensation polymers made up of thousands of monosaccharide units
Protein
- a poly die or polypeptide that is a polymer built from amino acid monomers
Dipeptide
A compounds formed from two amino acids
Protein complementarity
Combining foods that complement essential to amino acid content so that the total diet provides a complete supply of amino acids used for protein synthesis
Micronutrients
Substances that are needed only in mini use amounts but are essential in life
Vitamins
Organic compounds with a wide range of physiological functions
Coenzymes
Molecule that work in conjunction with enzymes to enhance their activity
Basal metabolic rate (BMR)
The minimum amount of energy required daily to support basic body functions
Nitrogen-fixing bacteria
They remove nitrogen gas from the air and convert is into ammonia
Denitrification
The process of converting nitrogen to nitrogen gas
Food surveillance
Random samples of food and produce are taken from farms or grocery stores, and analyzed for residues of chemicals and/or microbes
Total diet surveys
Samples of consumers’ meals are analyzed for contaminants
Enforcement sampling
Samples are taken when/where there is a concern that a food safety problem may exist, and this might lead to a food recall
Food borne illnesses
The presence of bacteria, viruses, parasites, and chemical toxins that can go undetected in our foods
Anabolism
Small molecules used to build up macromolecules
Catabolism
Large molecules cleaved into smaller ones
Glycolysis: glucose -> 2 pyruvate acid molecules
6C -> 2 *3C
Catabolism and anabolism together
They can be separate, but are not identical. They can be reversed but run through completely different pathways
- handled on separate pathways because if these processes were reversible there would be much wasted resources inside the cell
Reductive vs. oxidative
Reductive is from anabolic reactions requiring electrons (NADPH/NADP^+)
Oxidative is from catabolic reactions yielding electrons which causes a electron carrier (NAD/NADH)
Why are reductive and oxidative not the same
Because the reactions are different. One yields electrons and one requires electrons so the donor or electron transporter is not the same
Malnutrition
When you do not get sufficient nutrients
- Calorie intake may be fine, but if they do not have the right nutrients (empty calories) in it then you can suffer from malnutrition
Lipids
•Lipids in biological systems can be hydrophobic or amphipathic.
•Hydrophobic lipids, not surprisingly, are hydrophobic.
•Amphipathic lipids have a polar group (head) and a hydrophobic group (tail) and are utilized in membranes and energy storage. If the polar group has a carboxylic acid moiety, this is a fatty acid.
•Fatty acids can be saturated or unsaturated.
•Saturated fatty acids have only single carbon-carbon bonds.
•Unsaturated fatty acids have at least one double carbon-carbon bond.
•Monoumsaturated fatty acids have one double carbon-carbon bond
•Polyunsaturated fatty acids have more than one double carbon-carbon bond.
Lipid structure
- all double bonds have a cis configuration
- A cis bond is when it comes from a biological origin and has a Carbon that is double bonded
- a trans bond is when it has a c double bonded with the Hydrogens on opposite ends
What does a double bond cause? And what does it prevent?
A double bond causes severe “kinks” in the molecules and prevents close packaging
- kinking is when the double bond is not straight
Lipid nomenclature
• Lipids have common names , e.g., myristic acid.
• The systematic name takes into account the number of carbons in the hydrophobic chain, e.g., tetradodecanoic acid for the 14 carbons of myristic acid.
• The symbol nomenclature takes into account the number of carbons in the chain and the number of unsaturated bonds. Myristic acids is described by 14:0, meaning there are 14 carbons and no unsaturated bonds.
• Linoleic acid has 18 carbons and two double bonds, one between C9 and C10, and the other between C12 and C13. The systematic name is 9,12- octadecadienoic acid. The symbol nomenclature is 18:2 (9,12).
• Carbon counting starts at the carboxylic acid carbon in the delta counting system. Carbon counting starts at the carbon end in the omega counting system. Thus linoleic acid is a delta-9,12 or an omega-6,9 fatty acid.
How does the chain length effect melting and boiling point?
- when the chain is lengthened the melting point goes up. This is because with the increase in carbons it needs more energy to separate the molecules.
- there are also more bonds - when you increase the number of double bonds the melting point decreases because the amount of pacing lessens
Triaclyglycerols (triglycerides)
•Function as energy storage molecules, not as membrane components.
•Triacylglycerols are a main component of fats and oils.
•Different oils contain different types of triacylglycerols. (see Figure 11.7 in your textbook.) •Fats are used for energy storage because they are are less oxidized than carbohydrates. When completely oxidized, they yield more energy than carbohydrates.
Glycerophospholipids (I)
Also called phosphoglycerides.
- These are the major components of biological membranes.
- The molecules are glycerol-3-phosphate, with the C1 and C2 positions esterified with fatty acids. Also, the phosphate group on C3 sometimes is coupled to another group.
- If the C3 phosphate is not coupled to another group, the molecule is phosphatidic acid, which is not found in large amounts in biological membranes.
Glycerophospholipids (2)
- a common constituent of membranes is 1 - stearoyl - 2-oleoyl-phosphatidylcholine
- one of the three chains is unsaturated, which is typical for biological membranes
Trans fat
- if it looks like it and is big than it isn’t allowed
- trans fat is allowed in 0.5g or less. If it is more than this than it shouldn’t be allowed to be sold in food even if it is labeled.
What are the “goals” of glycolysis
- to make two ATP per one glucose
- to turn 2NAD+ into 2NADH
2NAD+ + 4e^- + 2h^+ -> 2NADH
Glycolysis is a catabolic reaction and the metabolites lose electrons
What type of carb is cane sugar
Disaccharide
What is an ethylene monomer composed of and what is its mass?
An ethylene monomer is composed of 2 carbons and 4 hydrogens
2(12) + 4(1) = 28 g/mol
How to find the number of monomers in a polymer?
The number of monomers is the mass of the polymer/the mass of the monomers
How do you increase the length of a polymer
You increase the length of a polymer by adding more monomers per end group. You need to increase the [ethylene]/[R]
- so either increase [ethylene] or decrease [R] or both
How to find the average molar mass of the polymer
The average mass of the polymer is found by doing the mass of each monomer multiplied by the average number of the monomers of each polymer
Example:
30,000 monomers * 28(g/ mol monomers) = 84,000g/mol
What does branching a polymer do
Branching would make the product more pliable and less rigid, so therefore making it better suited for a water pouch
The four protein folding levels
- Proteins fold into stable three‐dimensional shapes, or conformations, that are determined by their amino acid sequence. The complete structure of a protein can be described at four different levels of complexity: primary, secondary, tertiary, and quaternary structure.
The protein folding level - primary
Primary structure is the unique and linear sequence of amino acids in a protein. It is the sequence in which amino acids are added to a growing polypeptide during translation.
With 20 different amino acids, the number of primary sequences is almost infinite.
It is the primary structure that determines how (and where) the polypeptide will fold to give a protein its shape. Thus, primary structure determines the higher levels of protein structure.
Small changes in primary structure can result in large changes in protein shape and function.
The protein folding level - secondary
Secondary structure describes regions where the polypeptide is folded into localized shapes. There are two types of secondary structure (alpha helix and Beta pleated sheet).
The alpha helix is a delicate coil formed by hydrogen bonding between a hydrogen atom on one amino acid and an oxygen atom on the fourth amino acid away.
The beta sheet results from hydrogen bonding between different polypeptide chains or between different sections of the same polypeptide.
The protein folding levels tertiary
Tertiary structure is the overall shape of the protein. Most proteins (e.g. lysozyme, hemoglobin and insulin) have a compact, globular tertiary structure.
Some proteins are fibrous. Fibrous proteins like collagen (tendons, cartilage) and keratin (hair, feathers, horns, hoofs, etc.) have the alpha helix formation over their entire length. Other fibrous proteins like fibroin (the structural protein of silk) are dominated by beta sheets.
Tertiary structure is influenced by ionic bonds between opposite charged R-groups, hydrogen bonds between R-groups bearing opposite partial charges, and hydrophobic interactions resulting from the tendency of nonpolar R-groups to stay close together in an aqueous solution.
Another important bond affecting tertiary structure occurs in proteins that contain the amino acid cysteine. Where two cysteine monomers are close together, the sulfur of one cysteine bonds to the sulfur of the other, forming strong covalent bonds known as disulfide bridges.
The protein folding - quaternary level
Quaternary structure occurs in proteins that are made up of more than one polypeptide chain.
Combining different polypeptides leads to a greater range of biological activity. Collagen, for example, is made of three subunits intertwined into a triple helix, and hemoglobin is made of four heme groups, each a different polypeptide.
An influence on the quaternary structure of some proteins is the presence of a prosthetic group: a small molecule that is not a peptide but that tightly binds to the protein and plays a crucial role in its function. For example, the four heme groups on a hemoglobin protein are prosthetic and they function to carry oxygen.
Proteins with prosthetic groups are called conjugated proteins.
Explain the significance of the difference between polar and non-polar amino acids
The 20 different amino acids vary in their R groups; some R groups are non-polar, others are polar.
Polar amino acids have R groups that carry either a (+) or a (-) charge.
Polar amino acids are hydrophilic and non-polar amino acids are hydrophobic.
Hydrophobic R-groups stay close together in water.
Proteins with a lot of polar amino acids are soluble in water, and those with many non-polar amino acids do not dissolve in water.
The hydrophilic and hydrophobic properties of amino acids cause proteins to twist into useful shapes. This ability of proteins is important for cellular membranes.
Membrane proteins are firmly anchored in the phospholipid bilayer because they have two polar ends and a non-polar center. One end of a membrane protein contacts the watery extracellular fluid and the other end extends to the watery cytoplasm. The non-polar center remains inside the membrane because it is hydrophobic.
Protein channels facilitate the passage of polar molecules across cellular membranes because the polar amino acids line the inside of the channel and non-polar amino acids line the outside.
The polarity of R groups plays a role in the tertiary structure of globular proteins. Thus, polarity plays a role in shaping enzymes and their active sites.
How sickle cell anemia is associated with hemoglobin and the quaternary structure
- sickle cell anemia is a mutation of the Hemoglobin S where the quaternary structure can mold together
- this causes the hemoglobin structures to begin to struggle
- then the structure gets so big and the tetras groups form together that they start to elongate and mold until the effect is a severe loss of function
What is sickle cell caused by
Abnormal hemoglobin called sickle hemoglobin or hemoglobin S. Sickle hemoglobin is the result of a point of mutation in the beta glob in chain. This mutation replaces A with T as codon 6 of the beta hemoglobin chain. This can cause a major cost of a shift which switches from glutamic acid to valine amino acid
The 4 levels of protein folding
1) the amino acid sequence
2) the alpha helixes are sheets
3) the secondary structure motifs are folded together
4) several proteins form multi-subunit assemblies
Salad dressing
- salad dressing is an example of a hydrophobic reaction where water can be excluded. When the solution is mixed it gets shocked, then when it sits the solution settles
- when the water is excluded from a hydrophobic reaction with proteins and receptors the entropy increases
