Question

final exam study guide:
name:kenned cavalier date:dec 10,2006
1 what is the function of the chloroplast?

1. what is the function of the mitochondria?
2. what is the function of the ribosomes?
3. what is the function of the cell membrane?
4. what is the function of the lysosomes?
5. what is the function of the endoplasmic reticulum?
6. what do mitochondria and chloroplast have in common?
7. what is the difference between the cell membrane and the cell wall?
8. what is the function of nucleus?
9. in which organelle would you expect to find the most mitochondria? (red blood cells, muscle cells, nerve cells?).

Explanation:

The questions are about cell organelles and their functions, which falls under Biology (a subfield of Natural Science). Let's answer question 1 as an example: Chloroplasts are organelles in plant cells (and some algae) that perform photosynthesis, converting light energy into chemical energy (glucose) and also contain chlorophyll.

Answer:

1. The function of the Chloroplast is to carry out photosynthesis, using light energy to convert carbon dioxide and water into glucose (chemical energy) and oxygen, and it contains chlorophyll for light absorption.
2. The function of the Mitochondria is to produce energy (in the form of ATP) through cellular respiration, often called the "powerhouse of the cell".
3. The function of the Ribosomes is to synthesize proteins by translating messenger RNA (mRNA) into polypeptide chains.
4. The function of the Cell membrane is to regulate the movement of substances (like nutrients, wastes, ions) in and out of the cell, maintain cell structure, and act as a selective barrier.
5. The function of the Lysosomes is to contain digestive enzymes to break down waste materials, cellular debris, or foreign invaders (like bacteria) in the cell (acts as a "cellular stomach" or recycling center).
6. The function of the Endoplasmic Reticulum (ER): Rough ER (with ribosomes) is involved in protein synthesis and processing; Smooth ER is involved in lipid synthesis, detoxification, and calcium storage.
7. Mitochondria and Chloroplast both have their own DNA (are semi - autonomous), are involved in energy conversion (mitochondria: cellular respiration, chloroplast: photosynthesis), and have double - membrane structures.
8. Cell membrane: Found in all cells (plant, animal, prokaryotic), is a flexible, lipid - bilayer (with proteins) that is selectively permeable. Cell wall: Found in plant cells, fungi, bacteria, is a rigid, outer structure (made of cellulose in plants, chitin in fungi, peptidoglycan in bacteria) that provides structural support and protection; it is fully permeable to small molecules.
9. The function of the Nucleus is to store the cell's genetic material (DNA), control cell activities (like growth, metabolism, reproduction) by regulating gene expression, and is the site of DNA replication and transcription.
10. Muscle cells would have the most mitochondria because they require a large amount of energy (ATP) for contraction and movement.