Breaking and Rearranging of Molecules - Cell Energy

What are reactants in a chemical equation?

• Substances present at the end of a chemical equation

• The number in front of a molecule

• The arrow in a chemical equation

• Substances present at the start of a chemical equation

Answer explanation

Reactants are the substances that are present at the start of a chemical equation, as they undergo a chemical change to form products. Therefore, the correct choice is 'Substances present at the start of a chemical equation'.

Tags

NGSS.MS-PS1-1

What does the arrow (→) in a chemical equation represent?

• The number of molecules

• The start of the equation

• Yields / Equals / Makes

• The end of the equation

Answer explanation

In a chemical equation, the arrow (→) indicates the direction of the reaction, meaning it represents what the reactants yield or produce, thus it signifies 'Yields / Equals / Makes'.

What is a coefficient in a chemical equation?

• The arrow in a chemical equation

• The number in front of a molecule indicating the # of that molecule present

• The number below and to the right of an atom

• The substances at the end of a chemical equation

Answer explanation

A coefficient in a chemical equation is the number in front of a molecule, indicating how many of that molecule are present. This helps balance the equation and shows the relative amounts of reactants and products.

Tags

NGSS.MS-PS1-5

What does a subscript in a chemical formula indicate?

• The start of a chemical equation

• The end of a chemical equation

• The number of atoms of a particular element in a molecule

• The number of molecules

Answer explanation

A subscript in a chemical formula indicates the number of atoms of a particular element in a molecule. For example, in H2O, the '2' indicates there are two hydrogen atoms in each water molecule.

Why must chemical equations be balanced?

• So that there are similar amounts created

• To make the reactants disappear

• To ensure the same amount of each element is present in both reactants and products

• To ensure the products are more than the reactants

Answer explanation

Chemical equations must be balanced to ensure the same amount of each element is present in both reactants and products, adhering to the law of conservation of mass. This means matter is neither created nor destroyed in a chemical reaction.

Tags

NGSS.MS-PS1-5

What is the main purpose of cellular respiration?

• To break down glucose and oxygen into ATP

• To create glucose

• To create sucrose

• To produce water

Answer explanation

The main purpose of cellular respiration is to break down glucose and oxygen to produce ATP, which is the energy currency of the cell. This process is essential for powering cellular activities.

Tags

NGSS.MS-LS2-3

NGSS.MS-LS1-3

What are the waste products of cellular respiration?

• Glucose and oxygen

• Carbon dioxide and water

• Sucrose and ATP

• Hydrochloric acid and water

Answer explanation

The waste products of cellular respiration are carbon dioxide and water, which are produced when glucose is broken down for energy. This process occurs in cells to generate ATP, while releasing CO2 and H2O as byproducts.

Tags

NGSS.MS-LS2-3

What happens to sucrose in the digestive system?

• It is converted into carbon dioxide

• It remains unchanged

• It is broken down into glucose

• It is converted into ATP

Answer explanation

In the digestive system, sucrose is broken down by enzymes into glucose and fructose, which can then be absorbed into the bloodstream. Thus, the correct answer is that it is broken down into glucose.

Tags

NGSS.MS-LS1-7

What is the role of enzymes in the digestive system?

• To balance chemical equations

• To create glucose

• To produce ATP

• To break down food molecules

Answer explanation

Enzymes play a crucial role in the digestive system by breaking down food molecules into smaller, absorbable units. This process is essential for nutrient absorption and overall digestion.

Tags

NGSS.MS-LS1-7

What is the main product of photosynthesis?

• Water

• Glucose

• ATP

• Carbon dioxide

Answer explanation

The main product of photosynthesis is glucose, which plants produce using sunlight, carbon dioxide, and water. This glucose serves as an energy source for the plant and is essential for growth.

Tags

NGSS.MS-LS1-6

NGSS.MS-LS2-3