432 Exam 3

Exam 3

What is an anomeric carbon?

A carbon that has two forms (anomers). During cyclization, the carbon can change chirality into alpha and beta anomers. Cyclization occurs when the hetero oxygen is protonated and the ring is broken. The reformation of the ring is where the anomers appear.

What is a reducing sugar?

A linear sugar with an aldehyde (C(O)H) that can be oxidized to carboxylic acids (COOH). Aldehydes are good electrophiles and can be oxidized (gain/accept electrons). The sugar is not reduced, the sugar is the reducing agent. 

What is a pyranose sugar?

A sugar with a 6-membered ring

What is a furanose sugar?

A sugar with a 5-membered ring

What is the number assigned to an anomeric carbon?

1

What monosaccharides is maltose composed of and what is its linkage?

2 Glucose; α-1,4

What monosaccharides is sucrose composed of and what is its linkage?

1 glucose and 1 fructose; α-1,β-2

What monosaccharides is lactose composed of and what is its linkage?

1 galactose and 1 glucose; β-1,4

How are anomeric bonds named (α/β)?

Named based on hydroxyl orientation. β=up; α=down

In SNFG, what does a blue circle represent?

Glucose

In SNFG, what does a yellow circle represent?

Galactose

In SNFG, what does a green pentagon represent?

Fructose

What kind of bonds does glycogen and starch have?

Linear alpha-1,4 bonds and branching alpha-1,6 bonds

How is glucose chemically stored?

Covalently bonds to protein glycogenin

What is cellulose?

Linear chains of glucose with beta-1,4 linkage

Why can’t humans digest cellulose?

Cellulose is made of beta-1,4 glucose linkages. Humans don’t have beta-1,4-glucanases, or cellulase

What are glycosaminoglycans (GAGs)?

Repeated linear disaccharide units with an amino sugar and uronic acid.

What is hyaluronic acid degraded by?

Hyaluronidase

What is the function of chondroitin sulfate?

• Cartilage structure/function

• Joint shock absorption

• Connective tissue

What is the function of hylauronic acid?

• Extracellular matrix

• Vitreous humor of eye

• Joint lubrication

• Dermis

What is the function of heparin?

• Help mast cells store histamine

• Cell adhesion

• Bind to positively charged molecules

  • Help growth factors bind or inactivates them until heparin is degraded

What charge does heparin have and why?

Strongly negatively charged due to sulfation

What is antithrombin-binding pentasaccharide?

A deviation of herapin’s regular sugar sequence. 30% of heparin molecules contain one of these. It activates antithrombin III which inhibits clotting Factor Xa. 

What is the function of antithrombin-binding pentasaccharide?

Activates antithrombin III to inhibit clotting factor IIa. This is due to clotting factor IIa needing heparin to bind to ATIII and thrombin, resulting in an anticoagulant effect

How do ketone bodies lead to coma and death?

Increase blood pH which inhibits the binding of O2 to hemoglobin

What is a lipid?

A hydrophobic molecule with a high ratio of C/H to heteroatoms

What is the main function of lipids?

Energy storage

• Reduced compounds undergo oxidation

• Hydrophobic = condensed packing

Insulation

• Low thermal conductivity and high heat capacity

• Shock absorption

Membranes, Enzyme cofactors, Hormones, Pigmentation

What does it mean when a molecule is highly reduced?

Each atom in its structure can undergo more individual oxidation steps

Other than hydrophobicity, why is it more efficient to store energy as lipids/fatty acids as opposed to glucose?

For every carbon atom in a fatty acid, we get out more ATP molecules than the carbon atoms in glucose. This is because fatty acids are more reduced (have less C-O bonds)

Why are organs covered in a layer of fat?

To protect them from trauma by absorbing kinetic energy

What is a complex lipid?

A lipid containing a fatty acid; a long chain of C/H

What are the 2 classes of lipids?

Those not based on fatty acids

Those containing fatty acids (complex lipids)

What are the 2 classes of complex lipids?

Storage lipids (neutral)

Membrane lipids (polar)

Why are membrane lipids polar?

Part of them need to be in contact with water

What are the classes of membrane lipids?

Phospholipids

Glycolipid

Archaeal ether lipids

What are the classes of phospholipids?

Glycerophospholipids

Sphingolipids

What is the structure of glycerophospholid?

2 fatty acids and PO4-alcohol bound by glycerol

What is the structure of a phospholipid sphingolipid?

1 fatty acid and PO4-alcohol bound by sphingosine

What are the classes of glycolipids?

Sphingolipids

Galactolipids

What is the structure of galactolipids or sulfolipids?

2 fatty acids and a mono/disaccharide or SO4 bound by glycerol

What does saturated mean?

No double bonds; max amount of hydrogen bonded to each carbon

What is a monounsaturated fatty acid?

A fatty acid that has 1 double bond

What conformation of double bonds do most natural unsaturated fatty acids have?

Cis

What are polyunsaturated fatty acids?

Fatty acids with 2 or more double bonds

How are fatty acids named?

X:Y(Δ^q,r,s) n-Zanoic acid

• n = normal form (no branching)

• Z = nomenclature for number of carbons

• X:Y = X carbons and Y double bonds

• q,r,s = the numbers of the lowest carbon of the double bond

• Deprotonated ends in -ate 

• Omega is numbered in reverse direction

What is the trend between melting point and carbon chain length?

Melting point increases with carbon chain length

What is the trend between solubility and length of the carbon chain?

Solubility increases with carbon chain length

Between saturated and unsaturated fatty acids, which has a higher melting point and why?

Saturated fatty acids have higher melting points because they can be packed tighter which increases the energy needed to melt; unsaturated fatty acids are bent due to the double bond and are less efficiently packed

What type of lipid determines your blood type?

Glycosphingolipids

What are glycosyltransferaes

Transfer glycogroups to sphingolipids

If you have no glycosyltransferases what is your blo0d type

Type O

If you have glycosyltransferases for N-acetyl-galactosamine what is your blood type and what antibodies do you have?

Type A; Type B antibodies

What are the classes of eicosanoids

Prostaglandins

Thromboxanes

Leukotrienes

What is the function of prostaglandins?

Induction of Inflammation and fever

What is the function of leukotrienes?

Smooth muscle contraction in lungs

Why do eicosanoids have similar structures?

They all have arachidonate as a precursor

Cyclooxygenases 1 and 2 make which eicosanoids?

Prostaglandins and thromboxanes

How do NSAIDs affect the production of prostaglandins and thromboxanes?

NSAIDs inhibit COX 1 and 2 which are the enzymes used to produce prostaglandins and thromboxanes

How is asthma treated in relation to leukotrienes?

Inhibition of leukotriene receptors induces smooth muscle relaxation in the lungs

Is glycolysis catabolism or anabolism?

Catabolism

Is gluconeogenesis catabolism or anabolism?

Anabolism

What is anabolism?

The use of energy to build complex molecules

What is catabolism?

The break down molecules for energy

What are the reactants and products used in gluconeogenesis?

2 pyruvate + 4 ATP + 2 GTP + 2 NADH —> glucose

When do we perform gluconeogenesis?

When we have excess energy; uses more energy than is put out

Why is ATP used for energy

Thermodynamically stable

phosphates can activate other molecules

Provides right amount of energy to drive reactions

Is Pi and ADP or ATP more stable

Pi and ADP

What are the products of the Krebs cycle?

3 NADH

FADH₂

GTP

2 CO₂

What is the input for the Krebs/Citric acid cycle?

Acetyl-CoA

How does glucose become acetyl-CoA?

Glucose undergoes glycolysis to become pyruvate which is oxidized into Acetyl-CoA

What compartment does glycolysis take place in?

Cytoplasm

In what tissues does glycolysis take place in?

All tissues

Why does the brain, heart, and muscle tissues have an ATP buffer?

Constantly need ATP in case it gets too low because it cannot be created instantaneously

Glycogen is broken down into what molecule?

Glucose

Glycogen is synthesized from what molecule?

Glucose

What is the function of F26BP?

Stimulates PFK-1 and inhibits FBPase-1

What are the reactants of fatty acid biosynthesis?

1 acetyl-CoA + 7 malonyl-CoA

What tags proteins to be degraded by a proteasome?

The ubiquitin chain

Where does step 1 of the urea cycle occur?

The mitochondria

Where does steps 2-5 of the urea cycle occur?

The cytoplasm

11/14 after this card clinical nutrition

What are the primary goals of nutritional care in the inpatient setting

Reaction to the event and stabilization of the patient

What area the primary nutritional needs for patients

Energy: 25-35kcal/kg

Protein: 1/2-2 g/kg

Describe a cardiac diet

Low sodium (<2000 mg/day)

Low saturated fat

What is a renal diet?

Restricted in sodium, potassium, and phosphorus. Protein

may be restricted pre-dialysis or increased during dialysis

What is a consistent carbohydrate diet?

Provides a consistent amount of carbohydrates at each meal to manage blood glucose in patients with diabetes.

What conditions is a cardiac diet for 

CHF and MI

Describe a dysphagia diet

Texture modified diet consisting of pureed or mechanically soft foods with thickened liquid

Who is a dysphagia diet for?

Patients with difficulty swallowing as determined by a speech-language pathologist (SLP)

What is enteral nutrition (EN)?

Tube feeding. Nutrients deliverd bia tube into stomach/small intestine

What is parenteral nutrition (PN)?

Nutrients are delivered directly into the blood via IV

Compare/contrast enteral and parenteral nutrition

Enteral

• Maintains gut integrity

• Safer

• Less expensive

Parenteral

• Last resort when GI non-functional

How is

How is type 2 diabetes in ambulatory care managed with medical nutrition therapy?

How is cardiovascular disease in ambulatory care amanged with medical nutrition therapy

How is obesity and weight in ambulatory care managed with medical nutrition therapy?

How are GI disorders in ambulatory care managed with medical nutrition therapy?

What are the key ambulatory interventions in nutritional care?

• Education

• Counseling and behavior change

• Motivational interviewing

• Goal setting

• Addressing social determinants of health

What are the 3 pillars of nutritional needs

Energy

Protein

Fluid

What is the Mifflin-St Jeor Equation for men and women and what does it calculate?

Men: 10×weight (kg)+6.25×height (cm)−5×age (y)+5

Women: 10×weight (kg)+6.25×height (cm)−5×age (y)−161

Resting energy expenditure (REE)