Semester Review (Units 1-3)

Which subatomic particle determines the element?

• Electron

• Isotope

• Neutron

• Proton

Answer explanation

The proton is the subatomic particle that determines the element. Each element has a unique number of protons in its nucleus, known as the atomic number, which defines the element's identity.

Which of the following accurately identifies the reaction shown below?

• Adhesion

• Cohesion

• Dehydration Synthesis

• Hydrolysis

Answer explanation

Dehydration synthesis is a reaction where two molecules combine, releasing water. This process builds larger molecules from smaller ones, making it the correct choice for the reaction shown.

Which of the following is the main animal use of carbohydrates?

• Carrying genetic information

• Facilitating reactions

• Insulation

• Source of energy

Answer explanation

Carbohydrates primarily serve as a source of energy for animals. They are broken down into glucose, which fuels cellular processes, making this the main use of carbohydrates in animal physiology.

Which of the following can cause a protein to be denatured?

• All of these

• Extreme pH change

• High Temperatures

• Salt concentration

Answer explanation

All of these factors—extreme pH changes, high temperatures, and altered salt concentrations—can disrupt the interactions that maintain a protein's structure, leading to denaturation.

Which structure, found in both prokaryotes and eukaryotes, is responsible for protein production?

• Chloroplast

• Golgi Apparatus

• Mitochondria

• Ribosome

Answer explanation

Ribosomes are the cellular structures responsible for protein production in both prokaryotes and eukaryotes. They translate messenger RNA into polypeptide chains, making them essential for protein synthesis.

Which of the following cells do not have organelles?

• Animal

• Bacteria

• Fungi

• Plants

Answer explanation

Bacteria are prokaryotic cells that lack membrane-bound organelles, unlike animal, fungi, and plant cells, which are eukaryotic and contain various organelles. Therefore, the correct answer is Bacteria.

Which of the following methods of cellular transport moves solute from low concentration to high concentration?

• Active Transport

• Diffusion

• Facilitated Diffusion

• Osmosis

Answer explanation

Active transport is the only method that moves solutes against their concentration gradient, from low to high concentration, using energy. In contrast, diffusion, facilitated diffusion, and osmosis move substances from high to low concentration.

What is the name of the substance that is worked on by an enzyme?

• Active Site

• Allosteric Site

• Inhibitor

• Substrate

Answer explanation

The substance that is acted upon by an enzyme is called the substrate. Enzymes bind to substrates at their active sites to facilitate biochemical reactions.

Which of the following are the reactants of the photosynthesis reaction?

• Carbon Dioxide and Oxygen

• Carbon Dioxide and Water

• Glucose and Oxygen

• Glucose and Water

Answer explanation

The reactants of photosynthesis are Carbon Dioxide and Water. During this process, plants use sunlight to convert these reactants into glucose and oxygen, making the correct choice Carbon Dioxide and Water.

Where does the molecule being worked upon bind to the enzyme?

• Active Site

• Allosteric Site

• Competitive Site

• Noncompetitive Site

Answer explanation

The molecule binds to the enzyme at the Active Site, which is specifically designed for substrate binding, facilitating the enzyme's catalytic activity. Other sites like allosteric or competitive sites do not serve this primary function.