Homework questions on cells (yr 10 science)?

Question

Our science teacher gave us these questions on cells, I have no idea of how to answer them. Please help!

1. Enzymes control the rate at which chemical processes take place throughout the cell. Where are these enzymes made in the cell and how do they reach the parts of the cell where they are needed?

2. When examined under the electron microscope, a muscle cell is seen to have many mitochondria, how do you account for this?

3. Give arguments for and against a virus being a living thing.

Thank you sooo much for your time!

Answer 1

Hmm, well I'll help out as best I can.

1. Proteins are made in the ribosomes. They are trasported by vesicles and microtubules (if I remember correctly)

2. Mitochondria are the "power-houses" of the cell. They produce ATP which is the source of energy. Muscle cells need a lot more energy to function, so they have more mitochondria to produce more ATP.

3. This is a daft question...the term "life" isn't very scientific. There are some scientific definitions of life, which I don't buy into. Technically speaking viruses are not "alive" because they can't replicate by themselves...they need to hijack a cells replication mechanism. Your teacher will be happy if you say "Viruses can be considered alive because, though they can't replicate themselves, they can be thought of as parasites that DO make accurate copies of themselves via cell-hijacking".

/edit: I liked the living vs not-living answer of below poster (much better than mine). Careful about the golgi though - not all proteins wind up there. Golgi is used to modify and help fold proteins...it's not actually a transport mechanism (which is why I didn't mention it).

Answer 2

Enzymes are made on the ribosomes, usually attached to the rough endoplasmic reticulum. They are transported through the golgi via vessicles to where they are needed.

Muscle cells use a lot of energy, and they need it quickly in order to contract.

For living: They adapt, change, they have found a way to copy themselves, they contain dna or rna. They use many of the mechanisms that true organisms do, but they just borrow it from a host.

For non-living: They do not reproduce on their own, they need help, they do not consume nutrients to fuel themselves, they do not "die" although they can be destroyed.