Chapter 24 Metabolism

What is a nutrient

A chemical substance in food needed for body growth, repair, maintenance, and energy

What is the difference between an essential nutrient and nonessential nutrient

Essential nutrients must be consumed since the body can not produce them in sufficient quantities, unlike nonessential nutrients

What units are used to measure the energy provided by food

Measured in calories and kcals

Name the three macronutrients

Lipids, proteins, and carbohydrates

Define anabolism

The synthesis of larger molecules from smaller molecules

Define catabolism

Is the hydrolysis (breakdown) of larger molecules into smaller molecules

How are catabolism and anabolism related

Both of the metabolic reaction types take place within the cells. Catabolic reactions are used for ATP synthesis, while anabolic reactions are used for the storage of nutrients

Define metabolism

Chemical reactions of cells that involve nutrients

What is cellular respiration (aerobic respiration)

A set of catabolic reactions that provides cellular energy

What are the three metabolic pathways of cellular respiration

Glycolysis, the citric acid cycle (Krebs cycle), and oxidative phosphorylation

What is the main input of cellular respiration

glucose and oxygen

what is the main output of cellular respiration

ATP, water, and carbon dioxide

Are hydrogen ions lost during oxidation

Yes, hydrogen ions are lost

Are hydrogen ions gained during reduction

Yes, hydrogen ions are gained

Are NAD+ and FAD the oxidized or reduced forms of their molecules

Oxidized forms

Are NADH and FADH2 the oxidized or reduced forms of their molecules

Reduced forms

Which two metabolic pathways utilize substrate level phosphorylation

Glycolysis and Krebs cycle

Where does oxidative phosphorylation occur

Happens in the inner mitochondrial member

Which pathway of cellular respiration occur in the mitochondria

The Krebs cycle, electron transport chain, and oxidation phosphorylation

Which pathway of cellular respiration occurs in the cytoplasm

Glycolysis

Which stage of cellular respiration requires oxygen

The Krebs cycle and the electron transport chain

What is the starting input for glycolysis

1 glucose

What is the ending output of glycolysis

2 pyruvic acid

How much (net) ATP is produced by glycolysis

2 ATP

Is NADH oxidized or reduced during glycolysis

Reduced

How many molecules of NADH are produced during glycolysis

2 molecules of NADH+

Where will the NADH made during glycolysis be used later in cellular respiration

Used during the electron transport chain

After glycolysis, what is pyruvate to converted before moving to the citric acid cycle

Acetyl CoA

Is NADH made when pyruvate is converted

Produces 2 NADH molecules (one per a pyruvate)

What is the starting input for the citric acid cycle

1 acetyle CoA, 3 NAD+, and 1 FAD

Is NADH oxidized or reduced during the Krebs cycle

NAD+ is reduced to NADH

How many molecules of NADH is produced during Krebs cycle

3 molecules of NADH+ is produced

Is FADH2 oxidized or reduced during the Krebs cycle

FAD is reduced to FADH2

How many molecules of FADH2 is formed during the Krebs cycle

1 molecules of FADH2 is formed

Where will the NADH and FADH2 made during the Krebs cycle be used later in cellular respiration

Used for the electron transport chain

What is the role of NADH and FADH2 in the electron transport chain

Used to bring high-energy electrons as well as hydrogen atoms to the chain, which are used to produce water and pump hydrogen ions against the concentration gradient for energy

Where does the electron transport chain happen in the cell

The intermembrane space of the mitochondria

What is the goal of the electron transport chain

Allows the generation of energy from hydrogen ions down an electrochemical gradient to power ATP synthesis

What is the function of ATP synthase

Allows for the proton to flow their concentration gradient, which cranks the subunit rotor, converting ADP +Pi to ATP

From where does the energy for oxidative phosphorylation by ATP synthase come

Comes from the electrochemical gradient of H+ ions in the inner mitochondrial membrane

Which organ plays a major role in the regulation of plasma cholesterol levels

Liver (cholesterol)

Where in the body are most drugs and toxins metabolized

Liver (toxins)

Which macronutrients and micronutrients are regulated by metabolic functions of the liver

Processes almost every macronutrient and stores vitamins and micronutrients

Name three types of molecules that are formed from cholesterol

Bile salts, steroid hormones, and vitamin D

Name a structure our cells that requires cholesterol for its functioning

Plasma membrane

What is the function of LDLs (low density lipoproteins)

Used to transport cholesterol to peripheral tissues for storage or hormone synthesis

What is the function of HDLs (High density lipoproteins)

Used to transport cholesterol from peripheral tissues to liver to be broken down and secreted into bile

What is consider a healthy level of HDL

>60 mg/dl

What is consider a healthy level of LDL

<100 mg/dl

What is a bad level of HDL

<40 mg/dl

What is a bad level of LDL

>130 mg/dl

Which is considered the “good cholesterol”

HDL