which organelle is responsible for making proteins

HESI A2

Biology HESI A2 Practice Test

1. Which organelle is responsible for making proteins?

A. Ribosome
B. Chloroplast
C. Lysosome
D. Mitochondrion

Correct answer: A

Rationale: Ribosomes are the organelles responsible for protein synthesis within the cell. They are the sites where amino acids are linked together to form proteins based on the instructions carried by mRNA (messenger RNA). Ribosomes can be found free-floating in the cytoplasm or attached to the endoplasmic reticulum, and they play a crucial role in translating genetic information into proteins. Chloroplasts are responsible for photosynthesis, lysosomes are involved in digestion and waste removal, and mitochondria are known as the powerhouse of the cell responsible for energy production through cellular respiration. Therefore, the ribosome is the correct organelle responsible for making proteins.

2. What is the main function of the ribosomes in the cell?

A. DNA Replication
B. Protein Synthesis
C. Lipid Breakdown
D. Cell Division

Correct answer: B

Rationale: The correct answer is B: Protein Synthesis. Ribosomes are cellular organelles responsible for synthesizing proteins. This process is crucial for various cellular functions. Choice A, DNA Replication, is incorrect as ribosomes are not involved in this process. Choice C, Lipid Breakdown, is also incorrect as ribosomes do not play a role in lipid metabolism. Choice D, Cell Division, is incorrect as ribosomes are not directly involved in the process of cell division.

3. Which is true of gametes?

A. They are diploid cells
B. They are haploid cells
C. They are somatic
D. A & C are true

Correct answer: B

Rationale: Gametes are sex cells (sperm and eggs) that are involved in sexual reproduction. They are haploid cells, meaning they have half the number of chromosomes (n) compared to diploid cells. This is necessary for the formation of a diploid zygote when two gametes unite during fertilization. Somatic cells are non-reproductive cells in the body, so they are not gametes. Choice A is incorrect because gametes are not diploid but haploid. Choice C is incorrect because gametes are not somatic cells.

4. Why does cellular respiration happen?

A. Cells can copy DNA
B. Cells can breathe
C. Cells can convert nutrients to energy
D. Cells can divide

Correct answer: C

Rationale: Cellular respiration is the process through which cells break down nutrients such as glucose to produce ATP (adenosine triphosphate), the energy currency of the cell. This process allows cells to extract energy from food molecules and use it for various cellular activities and functions. Choices A, B, and D are incorrect because cellular respiration is specifically about converting nutrients to energy, not about DNA copying, breathing, or cell division.

5. Which of these molecules contains glucose?

A. Proteins
B. Lipids
C. Nucleic acids
D. Carbohydrates

Correct answer: D

Rationale: Glucose is a type of simple sugar and is classified as a carbohydrate. It is commonly found in various carbohydrate-containing foods such as fruits, vegetables, grains, and sugary snacks. Therefore, the molecule containing glucose would be a carbohydrate, making choice D the correct answer. Proteins (choice A) are made up of amino acids, lipids (choice B) are fats, and nucleic acids (choice C) are DNA and RNA, none of which contain glucose.