Week 3/4: Acids/Bases, Organic Chem, Cells

Question 1

Why is maintaining pH important?

Answer 1

Regulates chemical environment necessary for optimal cellular function, vital for health (buffer systems).

Question 2

What 3 mechanisms are responsible in the acid-base balance?

Answer 2

Buffer system (control of H+ ions), respiratory system (CO2 exhalation), renal system (H+ excretion)

Question 3

What is the function of buffers and what are three important ones?

Answer 3

Buffers are substances that help stabilize and regulate pH and prevent drastic changes. Important = protein, phosphate, bicarbonate.

Question 4

Give examples of inorganic/organic molecules.

Answer 4

Water, ammonia, acids/proteins, hormones, lipids

Question 5

Describe aldehydes.

Answer 5

Contain a terminal carbonyl group (C=O) making this part of the molecule reactive, polar, hydrophilic.

Question 6

Describe ketones.

Answer 6

Same as aldehydes but not terminal, so less reactive, polar, hydrophilic. Result from protein metabolism.

Question 7

Describe alcohols.

Answer 7

Involved in fermentation & metabolism, contains a hydroxyl group. Makes polar, hydrophilic, can form hydrogen bonds, soluble.

Question 8

Describe carboxylic acids.

Answer 8

Found in fatty acids, amino acids. Contains a carboxyl group (combo of carbonyl, hydroxyl). Weak acids, highly reactive, polar, hydrophilic.

Question 9

Describe aminos.

Answer 9

Found in amino acids, vitamins, neurotransmitters. Contain -NH2 attachment. Reactive, polar, hydrophilic.

Question 10

Describe the amino acid structure.

Answer 10

Building blocks of proteins, needed to build muscle, make hormones. Humans need 21 amino acids, 9 must be obtained from diet. Contains amino, carboxyl, R-group.

Question 11

Describe the 5 types of proteins.

Answer 11

Structural = provide structural support ex. collagen, keratin.
Regulatory = hormones, neurotransmitters ex. insulin, substance P
Contractile = MSK ex. actin, myosin
Immunological = protects body from pathogens, ex. antibodies, cytokines
Transport = carry substances ex. albumin, hemoglobin
Catalytic = work as enzymes ex. amylase

Question 12

Describe the 4 different levels of protein structural organization.

Answer 12

Primary = chain of peptides
Secondary = A-helix, B-sheet
Tertiary = mix of 2/3
Quaternary = mix of tertiary, multiple subunits

Question 13

Describe carbohydrates.

Answer 13

Organic molecules containing CHO, primary macronutrient. Examples = sucrose, starch, glycogen.

Question 14

Differentiate between monosaccharides, disaccharides, polysaccharides.

Answer 14

Mono = simplest form of carbs, either pentose (ex. deoxyribose, ribose) or hexose (ex. gluc, fruc, galac)
Di = 2 monos together by dehydration synthesis by glycosidic bond
Poly = long chain of monos, usually insoluble. Ex. glycogen, starches, cellulose

Question 15

What are the two carbohydrate-induced infant digestive disorders?

Answer 15

Lactose intolerance (lack of lactase), fructosemia (unable to break down fructose, + fructose in blood)

Question 16

What are some functions and physical properties of lipids?

Answer 16

Functions = protect organs, cell membranes, chemical messengers, store energy in fat cells.
Properties: hydrophobic, non-polar, insoluble

Question 17

Describe fatty acids.

Answer 17

HC chains with terminal carboxyl (COOH) attachment.

Question 18

What is the difference between unsaturated and saturated fatty acids?

Answer 18

Saturated = max # of hydrogen attachments
Unsaturated = one or more double bonds. Mono = one, poly = multiple

Question 19

What is the difference between omega and alpha ends?

Answer 19

Alpha end on a fatty acid = carboxyl attachment.
Omega end = no carboxyl

Question 20

What are sphingolipids?

Answer 20

Type of lipid found in cell membranes, specifically nerve cells, brain tissue. Have an alcohol and amine attachment.

Question 21

What are sphingomyelins?

Answer 21

Type of sphingomyelins are found in nerve cell membranes, consist of 25% of lipids in myelin sheaths.

Question 22

What are eicosanoids?

Answer 22

Fatty acids that signal cell and tissue functions. Derived from unsaturated precursor fatty acid, arachidonic acid.

Question 23

What are glycerides?

Answer 23

Lipids that contain fatty acids and glycerol. They react with glyceol to form ester bonds.

Question 24

What are triglycerides?

Answer 24

Most common lipid in body, provide protection, insulation, energy.

Question 25

What are phospholipids and their three functions?

Answer 25

2 fatty acids and a glycerol/phosphate head. Form membrane structures, act as surfactant, energy transfer in mitocondria

Question 26

Describe the structure of steroids.

Answer 26

3 cyclohexanes and 1 cyclopentane fused together. Lipophilic, so require a transport protein.

Question 27

Give examples of steroids. What is the importance of cholesterol?

Answer 27

Sex hormones, mineracorticoids, glucocorticoids. All steroids are derived from cholesterol.

Question 28

The bicarbonate buffer system occurs _____ in RBC's and ____ in plasma. Which enzyme speeds up the reaction in RBC's

Answer 28

Quickly, slowly. Carbonic anhydrase.

Question 29

Hyperventilation is a sign of ___ pH, hypoventilation is a sign of ___ pH.

Answer 29

High, low

Question 30

What two acid/base functions occur within the kidneys?

Answer 30

1. excretion of fixed acids/H+ 2. reabsorption of bicarbonate

Question 31

What occurs in the proximal convoluted tube?

Answer 31

Bicarbonate can return to the blood via a transporter in the membrane of cells. H+ can leave the apical membrane through an Na/K+ pump. Sodium wants to escape.

Question 32

Name the characteristics of respiratory acidosis (excluding pH).

Answer 32

CO2 = high HCO3 = normal Compensation = renal has high H+ excretion, HCO3 reabsorption

Question 33

Name the characteristics of metabolic acidosis (excluding pH).

Answer 33

CO2 = normal HCO3 = low Compensation = hyperventilate

Question 34

Name the characteristics of respiratory alkalosis (excluding pH).

Answer 34

CO2 = low HCO3 = normal Compensation = renal decreased H+ excretion, decreased HCO3 reabsorption

Question 35

Name the characteristics of metabolic alkalosis (excluding pH).

Answer 35

CO2 = normal HCO3 = high Compensation = hypoventilate

Question 36

Which types of bonds are present in each structure of proteins?

Answer 36

Secondary= H bonds Tertiary = H, disulphide, ionic bonds Quaternary = all

Question 37

Why should aspirin be avoided during pregnancy?

Answer 37

Aspirin decreases synthesis and production of prostaglandins and thromboxane.

Question 38

What are the three eicosanoids and their functions?

Answer 38

Leukotriene = inflammation/infection Prostaglandins = contraction Thromboxane = vasodilation

Question 39

What are the two main groups of hormones?

Answer 39

Sex/pregnancy, metabolic

Question 40

Aromatase is an enzyme that catalyzes the final reaction to produce ______. Where is it located, and in which types of cells?

Answer 40

Etradiol. Located in ER of ex. ovarian granulosa cells, testicles, placenta, etc.

Question 41

Name the acronym "APGAR."

Answer 41

Appearance, pulse, response to catheter in nostril (grimace), activity, respiration

Question 42

Nucleic acids are large organic molecules are carry _____ info. Name two examples.

Answer 42

Genetic. DNA, RNA.

Question 43

Name the three parts of a nucelotide.

Answer 43

Pentose sugar, nitrogenous base, phosphate group.

Question 44

Name both pyrimidines and purines/their matching. What is different in RNA?

Answer 44

Adenine, thymine = purines, 2 H bonds. Cytosine, guanine = pyrimidines, 3 H bonds. Uracil replaces thymine in RNA.

Question 45

What is the function of RNA? Name some types.

Answer 45

Function is to transmit genetic code for protein creation from the nucleus to ribosomes. Ex. mRNA, transfer, ribosomal.

Question 46

What are the three steps of DNA replication?

Answer 46

Transcription, translation, polypeptides.

Question 47

What are mutagens? Name 3 examples.

Answer 47

Anything that cant damage DNA. Oxidizing agents, alkylating agent, UV rays.

Question 48

What are the three types of mutations of DNA?

Answer 48

point mutations, deletions, chromosomal translations.

Question 49

Name the function of the nucleus.

Answer 49

Large organelle that contains DNA, main functions are cellular division and control of genetic info.

Question 50

Name of the functions of the cytoplasm.

Answer 50

Contains organelles between plasma membrane and nucleus.

Question 51

What do ion channels do? Transporter/carrier proteins?

Answer 51

Ion channels allow specific ions to move through pores. T/C proteins selectively move substances through membrane.

Question 52

What are the three forms of transport across the cell membrane? Describe.

Answer 52

Passive = concentration gradient through diffusion. Hydrostatic pressure = mech. force of water pushing against membranes. Active = cellular energy used to drive substance against gradient

Question 53

What do proteasomes do?

Answer 53

Large protease structures within cytosol to remove faulty proteins.

Question 54

What are the functions of lysosomes? Peroxisomes?

Answer 54

Lysosomes: digest organelles/cells, can do outside body. Peroxisomes: detoxify drugs/alcohol, found in large quantities in the liver.