Exam 2 Flashcards
What are the base (smallest) units of carbohydrates? How are these units combined to form larger carbohydrate molecules?
Monosaccharide- carb consisting of a single sugar
Disaccharide- two sugar molecules
Together they are simple carbohydrates or simple sugars
How do we categorize carbohydrates? What are the primary monosaccharides, disaccharides, oligosaccharides and polysaccharides?
Simple Carbohydrates- Monosaccharites (Glucose, Furcturose, Galactose)
Disaccharides (Lactose, Sucrose, Maltose)
Complex Carnohydrates- Oligosaccharides {3-10 sugar units} (Raffinose, Stachyose)
- Polysaccharides {>10 sugar units} (Glycogen, Starch, Dietary Fiber
What is the significance of glucose to the body?
Glucose is the most abundant monosaccharide in the body, provides cells with a source of energy (ATP). Glucose is the preperfed energy source for the nerbous syatem and the sole source of energy for red blood cells.
What are example food sources for each of the mono and disaccharides?
Mono: Fructose: fruits and veggies Galactose: milk products Glucose: not found in many food sources Disaccharides: Lactose: milk Maltose: not found in many foods (brewing process) Sucrose: plants, sugar cane, beats,
What is starch? What is the difference between amylose and amylopectin?
Starch is converted glucose. Two types of starch amylose and amylopectin.
Amylose – consisteing of linear (unbranched) chain of glucose molecules
What is the difference between glycogen and starch?
Glycogen is a highly branched arrandement of glucose molecules. When the body is low on glucose the body turns to glycogen for energy.
Why is fiber important in our diets?
Nourishing cells to colon, promotes the selective growth of intestinal bacteria, protects against cardiovascular disease, obesity, and type 2 diabetes.
What are good food sources of fiber?
Whole grains, legumes, veggies, fruits, oats, barley, rice, bran, seeds, soy,
Functional Fiber
– fiber that is added to food to provide beneficial physiological effects
Dietary Fiber
Fiber that naturally occurs in plants
Total Fiber
combination of dietary and functional fiber
Discuss the digestive process for carbohydrates. Begin with significant events in the mouth and trace digestive activity all the way through fiber in the colon.
Chemical digestion of starch begins in the mouth. Enzymes amylase and almylopection released resulting in shortes polysaccharide chains called dextrins. Dextrins pass uncharnged from the stomch to the small intestine. Digestion of disaccharides takes place entirely in the small intestine.
What are the special enzymes located in the small intestine?
enterocytes
What is the collective term for these enzymes?
Disaccharides
What does our body do with galactose and fructose?
Breaks them into tow glucose molecules
What happens after carbohydrates are absorbed into circulation? Where do they go?
Glucose and Galactose are absorbed into the enterocytes by carrier dependent. Energy requiring and active transport. Fructose is absorbed be facilitated diffuisoin. Once absorbed, monosaccharides are circulated to the liver via hepatic portal system.
Explain how blood glucose is regulated after a meal is consumed.
a. What hormones are involved?
Insulin and Glucagon
b. What effects do these hormones exert?
Assist in blood glucose regulation and energy storage
c. What event triggers their release?
When meals provide more glucose than we require. Pancreas is a glucose stabilizer
e. What happens if blood glucose goes too low (hypoglycemic)?
Can make people feel nauseated, dizzy, anxious, lethargic, and irritable
what are dipeptides, tripeptides, oligopeptides and polypeptides?
Polypeptides- a stirng of more than 12 amino acids held together via peptide bond.
What are the four basic components of an amino acid?
- A central carbon atom bonded to a hydrogen atom
- A nitrogen- containing amino group (NH2)
- A carboxylic acid group (-COOH)
- R-Group: The portion of an amino acids structure that distinguished it from other amino acids
How are amino acids combined to form proteins?
Joined together by peptide bonds. Condensation reactine in which a hydroxyl group form one amino acid is joined with a hydrogen atom from another amino acid
What differentiates protein from other macronutrients chemically?
Proteins contain appreciable amounts of nitrogen which makes them chemically distinct
What does “conditionally essential” mean?
When nonessential amino acids become essential because they must be obtained fro the diet
What is transamination?
The process by which an amino group is formed via the transfer of an amino group from one amino acid to another organic compound
Describe complete vs. incomplete. Provide examples of each.
Complete: a food that contains all the essential amino acids in relative amounts needed by the body. Ex) meat, poultry, eggs, dairy
Incomplete: a food that lacks or contains very low amounts of one or more essential amino acids. Ex) plant products
Describe the concept of protein complementation. Provide an example.
Combining incomplete protein sources to provides all of the essential amino acids in relatively adequate amounts
Describe the four layers of protein structure.
Primary structure- primary sequence and is determined by the DNA code, determines the most basic chemical and physical characterisitcs
Secondary structure- folding of a protein becaue of weak bonds that form between elements of the amino acid backbone
Tertiary structure- folding of a plupeptide chain becaue of interactions amoung the R groups of the amino acid
Quaternary structure- the combinging of peptide chains with other peptide chains of a protien
What component or interaction plays the biggest role each layer of structure?
Primary
What is the term fro disruption of the 3-D structure of a protein?
denaturation