Anatomy and Physiology of the Respiratory System

What are the major categories of nutrients? Where do most carbohydrates, lipids, and proteins come from?

The major categories of nutrients include carbohydrates, lipids, proteins, vitamins, and minerals. Most carbohydrates come from plant sources, lipids from fats and oils, and proteins from animal and plant sources.

What is catabolism? Anabolism? What is ATP and why is it important?

Catabolism is the metabolic process that breaks down molecules to obtain energy, while anabolism is the process that builds molecules from smaller units. ATP, or adenosine triphosphate, is the energy currency of the cell, crucial for driving various biochemical reactions.

Describe glycolysis, the Krebs cycle, electron transport, & oxidative phosphorylation (chemiosmosis). What is ATP synthase and where would you find it? Where does glycolysis occur?

Glycolysis is the breakdown of glucose into pyruvate, occurring in the cytoplasm. The Krebs cycle generates electron carriers in the mitochondria, and the electron transport chain uses these carriers to create ATP through oxidative phosphorylation. ATP synthase is found in the mitochondrial membrane.

Where is pyruvate found? What can happen to it? What is fermentation? When is lactate (lactic acid) formed?

Pyruvate is found in the cytoplasm after glycolysis. It can be converted into acetyl CoA for the Krebs cycle or undergo fermentation to produce lactate when oxygen is scarce.

How much ATP is produced for every glucose molecule if glucose is completely metabolized?

If glucose is completely metabolized, up to 36-38 ATP molecules can be produced.

Fats can be broken down to acetyl CoA. What happens to acetyl CoA in mitochondria? What is the central molecule in fat metabolism? When are ketone bodies produced?

Acetyl CoA enters the Krebs cycle in mitochondria. The central molecule in fat metabolism is acetyl CoA. Ketone bodies are produced when fat oxidation is increased, often during fasting.

Where is oxygen used in the metabolism?

Oxygen is used during oxidative phosphorylation in the electron transport chain.

When are amino acids used to make ATP? What happens to the amino groups when amino acids are digested? What is urea and why is it important?

Amino acids are used to make ATP during periods of fasting or intense exercise. The amino groups are removed through deamination, forming urea, which is important for safely excreting excess nitrogen.

What is the role of the liver in metabolism? What does the liver make? Describe the functions of the liver.

The liver plays a central role in metabolism, producing bile, processing nutrients, detoxifying substances, and regulating blood sugar levels.

What is glycogenesis, glycogenolysis and gluconeogenesis, lipolysis?

Glycogenesis is the formation of glycogen from glucose, glycogenolysis is the breakdown of glycogen into glucose, gluconeogenesis is the synthesis of glucose from non-carbohydrate sources, and lipolysis is the breakdown of fats into fatty acids.

Why is cholesterol important? How do we obtain cholesterol? What is LDL, HDL?

Cholesterol is essential for cell membrane structure and hormone production. It can be obtained through diet and is also synthesized by the body. LDL (low-density lipoprotein) carries cholesterol to cells, while HDL (high-density lipoprotein) carries it away from cells to the liver for excretion.

What is substrate level phosphorylation and where does it occur?

Substrate level phosphorylation is a way of producing ATP by transferring a phosphate group to ADP during glycolysis and the Krebs cycle.

What is NAD+ and NADH + H+?

NAD+ is a coenzyme that acts as an electron carrier in metabolic reactions, while NADH + H+ is its reduced form, carrying energy to the electron transport chain.

Compare the absorptive state with the post-absorptive state.

The absorptive state occurs after eating when nutrients are entering the bloodstream; the body uses these nutrients for energy and storage. The post-absorptive state occurs when the body relies on stored energy due to fasting.

Energy may be stored as fats, carbohydrates, and proteins. True/False Which form contains the most energy per gram?

True. Fats contain the most energy per gram compared to carbohydrates and proteins.

What happens eventually to most of the energy that is derived from food?

Most of the energy derived from food is transformed into ATP, which the body uses for various functions.

Describe the functions of orexins, neuropeptide Y, galanin, and GLP-1.

Orexins stimulate appetite, neuropeptide Y increases food intake, galanin is associated with fat consumption, and GLP-1 promotes insulin secretion and reduces appetite.

What happens to the hydrogen ions that are passed down the electron transport chain?

Hydrogen ions are pumped across the mitochondrial membrane, creating a proton gradient that drives ATP synthesis.

What is the consequence of the breakdown of large amounts of fatty acids?

The consequence is the production of excess acetyl CoA, which can lead to the formation of ketone bodies.

What is oxidation and what is reduction?

Oxidation is the loss of electrons from a substance, while reduction is the gain of electrons.

Every time something is reduced, something else must be _

oxidized.

Every time something is oxidized, something else must be _

reduced.

Fatty acids can be used for gluconeogenesis (true/false).

False.

An overdose of insulin would lead to hypo- or hyper- glycemia?

It would lead to hypoglycemia.

Fatty acids are a preferred fuel for the heart (true/false).

True.

Amino acids are a preferred fuel for the brain (true/false).

False.

Describe some mechanisms involved in the regulation of body temperature.

Mechanisms include vasodilation, vasoconstriction, sweating, and shivering to maintain homeostasis.

What is the effect of 'pyrogens' on the hypothalamus?

Pyrogens induce fever by raising the body’s temperature set point in the hypothalamus.

During some fevers vaso (dilation/constriction) results in the 'chills'.

vasoconstriction.

What is the formula for pH?

pH is calculated as the negative logarithm of the hydrogen ion concentration: pH = -log[H+].