Chapter 2: chemical organization Flashcards
Introduce the language and fundamental concepts of chemistry as it relates to the human body. Discuss how chemical bonds form and how chemical reactions occur Compare and contrast organic and inorganic compounds Describe the structure, function and importance of the four main groups of macromolecules (carbohydrates, lipids, proteins and nucleic acids)
What chemical element constitutes the largest percentage of total body mass in humans?
Oxygen (O) - About 65% of total body mass.
What is the significance of oxygen in the human body?
Oxygen is crucial for cellular respiration, enabling the production of energy (ATP) from nutrients. It is also a major component of water and organic molecules.
Which element plays a major role in bone formation and makes up a significant percentage of total body mass?
Calcium (Ca) - About 1.5%. It is essential for the formation of bones and teeth, as well as muscle function, nerve signaling, and blood clotting.
What is the role of nitrogen in the human body, and what percentage of body mass does it comprise?
Nitrogen (N) - About 3%. It is a key component of amino acids, proteins, and nucleic acids like DNA and RNA.
Which element is vital for the transport of oxygen in blood and is found in hemoglobin?
Iron (Fe) - It makes up less than 0.01% of body mass but is crucial for oxygen transport in hemoglobin and myoglobin.
Name the chemical element that is a key component of DNA and ATP, and indicate its percentage of body mass.
Phosphorus (P) - About 1%. Phosphorus is critical for the structure of DNA, RNA, and ATP, and is also important in the formation of bones and teeth.
significance of carbon in the body:
Forms backbone chains and rings of all organic molecules: carbohydrates, lipids (fats), proteins, and nucleic acids (D N A and R N A).
significance of hydrogen in the body:
constituent of water and most organic molecules; ionized form (H+) makes body fluids more acidic.
What are chemical elements?
Chemical elements are building blocks of matter, both living and nonliving, that cannot be split into simpler substances by ordinary chemical means.
How many chemical elements are normally present in the human body?
Twenty-six different chemical elements are normally present in the human body.
What percentage of the body’s mass is made up of major elements?
Major elements make up about 96% of the body’s mass.
Which four elements are considered the major elements in the human body?
Oxygen, carbon, hydrogen, and nitrogen.
What are the lesser elements, and what percentage of the body’s mass do they make up?
The lesser elements are calcium, phosphorus (P), potassium (K), sulfur (S), sodium, chlorine (Cl), magnesium (Mg), and iron (Fe). They make up about 3.6% of the body’s mass.
How much of the body’s mass is made up by trace elements?
Trace elements account for about 0.4% of the body’s mass.
How many trace elements are present in the human body?
There are 14 trace elements present in the human body.
Potassium significance (K):
0.35 % of total body mass; needed to generate action potentials.
Sulfur (S) significance:
0.25 % of TBM; Component of some vitamins and many proteins.
Sodium (Na) significance:
0.2 % of TBM; the most plentiful cation in extracellular fluid; essential for maintaining water balance; needed to generate action potentials.
Chlorine (Cl) significance:
0.2 % of TBM; the most plentiful anion (negatively charged particle) in extracellular fluid; essential for maintaining water balance.
Significance of Magnesium (Mg):
o.1 % of TBM; needed for action of many enzymes (molecules that increase the rate of chemical reactions in organisms).
When do chemical reactions occur?
when new bonds are formed, or old bonds are broken
what is a reactant?
starting substances
what is a product?
ending substances
What happens to bonds during a chemical reaction?
Old bonds break and new bonds form between atoms.
What is the relationship between the number of atoms before and after a chemical reaction?
The number of atoms of each element is the same before and after a chemical reaction.
In the reaction between hydrogen and oxygen, what are the reactants?
The reactants are two hydrogen molecules (H2) and one oxygen molecule (O2).
What are the products of the chemical reaction between hydrogen and oxygen?
The products are two molecules of water (H2O).
What does the arrow in a chemical reaction represent?
The arrow indicates the direction in which the reaction proceeds.
How is the mass of the reactants related to the mass of the products in a chemical reaction?
The total mass of the reactants equals the total mass of the products.
Why do the reactants and products have different chemical properties?
The atoms are rearranged during the chemical reaction, leading to different chemical properties for the reactants and products.
What is metabolism?
Metabolism refers to all the chemical reactions occurring in the body.
What is energy?
Energy is the capacity to do work.
What are the two principal forms of energy?
Potential energy (stored energy) and kinetic energy (energy in motion).
What is potential energy?
Potential energy is stored energy, like the energy in water behind a dam or a person poised to jump.
What happens to potential energy when it is released?
It is converted into kinetic energy.
What is chemical energy?
Chemical energy is a form of potential energy stored in the bonds of compounds and molecules.
What does the law of conservation of energy state?
Energy can neither be created nor destroyed, but it can be converted from one form to another.
How is the chemical energy in food used by the body?
It is converted into kinetic energy for activities like walking and talking.
What generally happens when energy is converted from one form to another?
Some energy is released as heat, which helps maintain normal body temperature.
What do chemical bonds represent?
Chemical bonds represent stored chemical energy.
What happens during a chemical reaction?
New bonds are formed or old bonds are broken between atoms.
What is an exergonic reaction?
An exergonic reaction releases more energy than it absorbs.
What is an endergonic reaction?
An endergonic reaction absorbs more energy than it releases.
What is activation energy?
Activation energy is the energy needed to start a chemical reaction.
How is energy released during a chemical reaction?
As new bonds form during the reaction, energy is released to the surroundings.
What are the two factors that influence activation energy?
Concentration of particles and temperature.
How does concentration affect the chance of a collision in a chemical reaction?
The higher the concentration of particles, the more likely they are to collide and cause a reaction.
How does temperature affect the movement of particles in a chemical reaction?
Higher temperature increases the speed of particles, making collisions more forceful and increasing the chance of a reaction.
What happens during a chemical reaction?
Particles collide and bonds either break or form.
Why can’t the body rely solely on temperature and molecule concentration to speed up reactions?
Raising temperature or concentration could damage cells.
What is a catalyst?
A catalyst speeds up a reaction by lowering the activation energy needed for a successful reaction.
How does a catalyst affect the energy difference between reactants and products?
A catalyst does not change the energy difference between reactants and products.
How does a catalyst help in a chemical reaction? (I.e: make reactions more efficient).
A catalyst ensures that particles collide in the correct orientation, making the reaction more efficient.
Does a catalyst get used up during a reaction?
No, a catalyst remains unchanged and can be reused for multiple reactions.
In the reaction A + B + C → AB + C, what role does C play?
C is the catalyst, as it is not used up in the reaction.
What are most catalysts in living cells called?
Most catalysts in living cells are protein molecules called enzymes.
What are the two parts of some enzymes?
The protein portion is called the apoenzyme, and the nonprotein portion is called the cofactor.
How do enzymes work?
Enzymes catalyze specific reactions with great efficiency by binding only to specific substrates, fitting like a key in a lock or adjusting shape around the substrate (induced fit).
What is the specificity of enzymes?
Each enzyme is highly specific, binding only to particular substrates and producing specific products.
How much can enzymes speed up reactions?
Enzymes can speed up reactions by 100 million to 10 billion times compared to reactions without them.
How many substrate molecules can a single enzyme convert into products per second under optimal conditions?
A single enzyme can convert between 1 to 600,000 substrate molecules into products per second under optimal conditions.
How is enzyme production and concentration controlled?
Enzyme production and concentration are controlled by cellular genes.
What can influence enzyme activity within a cell and how do enzymes exist?
Enzyme activity can be enhanced or inhibited by substances within the cell, and enzymes can exist in active or inactive forms depending on the cell’s chemical environment.
what do enzymes serve as?
catalysts that regulate the speed of chemical reactions.
what is and important factor to regulate enzyme activity?
Temperature. Individual enzymes have an optimal temperature at which they are most active.
What do chemical bonds represent in terms of energy?
Chemical bonds represent stored chemical energy.
What happens during a chemical reaction?
Chemical reactions occur when new bonds are formed, or old bonds are broken between atoms.
What is the difference between exergonic and endergonic reactions?
Exergonic reactions release more energy than they absorb, whereas endergonic reactions absorb more energy than they release.
What happens in the body’s metabolism regarding exergonic and endergonic reactions?
In the body’s metabolism, exergonic reactions and endergonic reactions are coupled, where energy released from exergonic reactions is used to drive endergonic reactions.
What typically happens during exergonic reactions in terms of nutrients?
Exergonic reactions typically occur when nutrients, such as glucose, are broken down.
What is a synthesis reaction?
A synthesis reaction is a process where two or more atoms, ions, or molecules combine to form new and larger molecules.
What does the word ‘synthesis’ mean?
The word ‘synthesis’ means “to put together.”
What are all the synthesis reactions in the body collectively called?
All the synthesis reactions in the body are collectively referred to as anabolism.
Are anabolic reactions typically exergonic or endergonic? Why?
Anabolic reactions are usually endergonic because they absorb more energy than they release.
