2023 Fall Semester Exam Review

The table in the image shows the effect of enzyme X on a substrate over time. The data in the table reveal that the role of the enzyme is to facilitate a reaction. The data further reveal that --

• once the substrate is exhausted, the enzyme transforms into the substrate

• once the supply of substrate is exhausted, the enzyme cannot cause a reaction to occur.

• once the supply of the substrate is renewed, the enzyme prevents the substrate from transforming into products.

• once the supply of substrates is renewed, the enzyme can cause the reaction to occur exactly as it did before.

_ _ _ _ _ _ _ _ _ _ _ are subunits of DNA molecules.

(a)  

Cells pass through a G₂ checkpoint before entering mitosis. If DNA is damage is detected, the cell does not enter mitosis until the damage is repaired. Why is DNA damage repaired before cells enter mitosis?

• So another round of DNA synthesis does not have to take place

• So that the cytoplasm can be divided equally between the two daughter cells.

• So that healthy daughter cells are produces, allowing the organism to continue growing.

Many enzyme end in -ase. Such as Ribulose bisphosphate carboxylase, lactase, amylase, but there are several that do not, such as pepsin - a digestive enzyme. However, all enzymes are necessary for life because they

• speed up chemical reactions

• lower the amount of energy needed to begin a chemical reaction

• act as a biological catalyst

• help break or make polymers

The cellular process in the image occurs in which stage of the cell cycle?

• G₁

• S

• G₂

• M

The image shows a nuclear process. What is the nuclear process shown that occurs prior to mitosis?

• Recombination

• Fertilization

• Mutation

• Replication

A (a)   required a host cell in order to reproduce.

Answer explanation

Viruses cannot reproduce on their own.

Viruses require a host cell in order to reproduce.

The virus will use the host cell to make new virus parts!

Which of the following characteristics would you expect to only find in a Eukaryotic cell?

• Mitochondria

• Freely floating DNA

• Chloroplast

• Ribosomes

Answer explanation

Eukaryotic cells have membrane bound organelles such as a mitochondria or a chloroplast.

Freely floating DNA is only found in Prokaryotic cells.

Ribosomes are found in all cell types.

When the cell cycle checkpoints are not working properly, what could happen?

• uncontrolled cell growth

• rapid cell growth

• unregulated cell growth

• tumor formation

Answer explanation

Check points are important in the cell cycle because they can prevent cancer cells from growing!

​ (a)   , such as glucose, provide us with a quick energy source.

​ (b)   , which include fats, store energy that can be broken down to yield large amounts of energy.

​ (c)   , which are composed of amino acids, help with muscle growth and repair.

​ (d)   , which include DNA and RNA, play a major role in the storage and expression of genetic information.

• Carbohydrates
• Lipids
• Proteins
• Nucleic acids