Lecture Quiz 3 Flashcards
<p>Define nutrient</p>
<p>a substance that promotes normal growth, maintenance, and repair</p>
<p>What are the major nutrients?</p>
<p>carbohydrates, lipids, proteins</p>
<p>What are other nutrients?</p>
<p>vitamins and minerals
| water</p>
<p>Define metabolism</p>
<p>all chemical reactions necessary to maintain life</p>
<p>What is an anabolic reaction?</p>
<p>synthesis of larger molecules from smaller ones</p>
<p>What is a catabolic reaction?</p>
<p>hydrolysis of complex structures into simpler ones</p>
<p>What happens during cellular respiration? (vague)</p>
<p>food fuels are broken down within cells and some of the energy is captured to produce ATP</p>
<p>What do enzymes do during cellular respiration?</p>
<p>shift the high energy phosphate groups of ATP to other molecules
these phosphorylated molecules are activated to perform cellular functions</p>
<p>What are the three major stages of metabolism?</p>
<p>digestion
anabolism
oxidative breakdown
occurs in the mitochondria</p>
<p>What happens during digestion?</p>
<p>breakdown of food
| nutrients are transported to tissues</p>
<p>What happens during anabolism of metabolism?</p>
<p>nutrients are built into lipids, proteins, and glycogen
| nutrients are broken down by catabolic pathways to pyruvic acid and acetyl CoA</p>
<p>What happens during oxidative breakdown of metabolism?</p>
<p>nutrients are catabolized to carbon dioxide, water, and ATP
complete breakdown of foods</p>
<p>What catalyzes redox reactions?</p>
<p>enzymes
| dehydrogenases</p>
<p>When does oxidation occur?</p>
<p>gain of oxygen
| loss of hydrogen</p>
<p>What is a rule of thumb for redox reactions?</p>
<p>whenever one substance is oxidized, another substance is reduced</p>
<p>What are the energy shifts in redox reactions?</p>
<p>oxidized substances lose energy
| reduced substances gain energy</p>
<p>What do coenzymes do in redox reactions?</p>
<p>act as hydrogen/electron acceptors</p>
<p>What are the two important coenzymes and what are they derived from?</p>
<p>nicotine adenine dinucleotide (NAD+) - derived from B3 niacin
Flavin adenine dinucleotide (FAD) - derived from B2</p>
<p>Where does substrate level phosphorylation occur?</p>
<p>cytoplasm and mitochondria</p>
<p>What happens during substrate level phosphorylation?</p>
<p>high-energy phosphate groups are transferred directly from phosphorylated sunstrates to ADP
ATP is synthesized in glycolysis and Krebs cycle</p>
What is oxidative phosphorylation?
only occurs in the mitochondria
uses chemiosmotic process whereby the movement of substances across a membrane is coupled to chemical reactions
Where does oxidative phosphorylation occur?
carried out by electron transport proteins in the cristae of the mitochondria
Give a brief overview of oxidative phosphorylation
nutrient energy is used to pump H+ into intermembrane space
steep diffusion gradient results
H+ ions flow back across membrane through ATP synthase
energy is captured and added to ADP
Where do the bile duct and main pancreatic duct join the duodenum?
hepatopancreatic ampulla
What are the bile duct and main pancreatic duct controlled by?
sphincter of Oddi
What is the purpose of the structural modifications of the small intestine?
increases surface area
ideal for absorption
What are the plicae circulares?
deep circular folds of the mucosa and submucosa
What are the villi?
fingerlike extensions of the mucosa
What are the microvilli?
tiny projections of absorptive mucosal cells plasma membranes
What is the epithelium of the mucosa of the small intestine made up of?
absorptive cells and goblet cells
enteroendocrine cells
interspersed T cells called intraempithelial lymphocytes (IELs)
What do IELs do?
release cytokines upon encountering Ag
What do the cells of intestinal crypts do?
secrete intestinal juice
What are found in the submucosa?
Peyer’s patches