Chapter 8: Metabolism Flashcards
- all chemical reactions that take place in cells to break down or build molecules
- Anabolism or catabolism
Metabolism
- a series of linked reactions, each catalyzed by a specific enzyme
- produce energy and cellular compounds
Metabolic Pathway
When we eat foods, it is digested to smaller molecules
- polysaccharides
- lipids
- proteins
As the glucose, fatty acids, and amino acids are broken down further, _____ is ______
energy is released
What happens to the energy from our foods since we do not use it all at once?
we store energy in the cells as high-energy adenosine triphosphate, ATP
ATP is later broken down obtain energy to do work in our bodies:
- contracting muscles
- synthesizing large molecules
- sending nerve impulses
- moving substances across cell membranes
Metabolism involves:
- Catabolic reactions
- Anabolic reactions
It break down large, complex molecules to provide energy and smaller molecules
Catabolic reactions
It uses ATP energy to build larger molecules
Anabolic reactions
Stages of Metabolism:
Catabolic reactions
Stage 1: Digestion and hydrolysis
Stage 2: Degradation
Stage 3: Oxidation
It break down large molecules to smaller ones that enter the bloodstream
Digestion and hydrolysis
It breaks down molecules to two- and three-carbon compounds
Degradation
________ of small molecules in the ____ ____ ____ and _______ _______ provide ATP energy
- Oxidation
- citric acid cycle
- electron transport
As long as the cells have oxygen, the hydrogen ions and electrons from the ______ _______ are transferred to electron transport to synthesize ATP
reduced coenzymes
Adenosine triphosphate (ATP)
- is the energy form stored in cells
- is obtained from the oxidation of food
It consists of adenine (nitrogen base), a ribose sugar, and three
phosphate groups
Adenosine triphosphate (ATP)
Requires ________ to convert ADP + Pito ATP
7.3 kcal/mol (or 31 kJ/mol)
Hydrolysis of ATP:
The hydrolysis of ATP to ADP releases 7.3 kcal (31 kJ)/mole
ATP → ADP + Pi + 7.3 kcal/mol (31 kJ/mol)
Hydrolysis of ATP:
The hydrolysis of ADP to AMP releases 7.3 kcal (31 kJ)/mole
ADP → AMP + Pi + 7.3 kcal/mol (31 kJ/mol)
Phosphate ester bond
Low energy bond
Phospho anhydride bonds
High energy bond
- Used in anabolic reactions
- The energy-storage molecule
- Coupled with energy-requiring reactions
ATP
Hydrolysis products
ADP + Pi
Oxidation:
Loss of electrons (e-)
Reduction:
Gain of electrons (e-)
Oxidation:
Loss of hydrogen (H or H+ and e-)
Reduction:
Gain of hydrogen (H or H+ and e-)
Oxidation:
Gain of oxygen
Reduction:
Loss of oxygen
Oxidation:
Release of energy
Reduction:
Input of energy
Participates in reactions that produce a carbonoxygen double bond (C=O)
NAD+ (nicotinamide adenine dinucleotide)
NAD+ contains
- ADP
- ribose
- nicotinamide
Reduces to _____ when the nicotinamide group accepts H+ and 2e-
NADH
Participates in reactions that produce a carbon-carbon double bond (C=C)
FAD (flavin adenine dinucleotide)
Reduced form of FAD
FADH2
FAD contains
- ADP
- riboflavin (vitamin B2)
Consists of pantothenic acid (vitamin B5), phosphorylated ADP, and aminoethanethiol
Coenzyme A
____ ___ ____ such as the two-carbon acetyl group for transfer
Activates acyl groups
What is the reactive feature of coenzyme A?
thiol group (-SH)
thiol group (-SH) bonds to a _____ ____ ____ to produce the energy-rich thioester ____ ___
- two-carbon acetyl group
- acetyl CoA
Used to transfer acetyl groups
Coenzyme A
The coenzyme after C=O bond formation
NADH + H+
