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VC BSC 1010c

Foxson

STUDY GUIDE – Exam 2– Covers Chapters 6-10

A tour through the Cell (Chapter 6)

- The discovery of what instrument allowed for the discovery of cells?

Microscope

- Who is credited with discovering the first microscope and coining the term “cell”?

Robert Hooke

- In general, how do microscopes function? What are the differences between how light

and electron microscopes work?

Microscopes function by passing light or a beam of electrons through a specimen

and then through glass lenses. A light microscope involves visible light being

passed through the specimen and then through the glass lenses, and the glass

lenses refract the light in a way that magnifies the image of the specimen as it is

projected into the eye. Electron microscopes involves a beam of electrons being

passed through the specimen or onto its surface instead of light.

- What are differences in how a TEM and SEM function?

A SEM creates an image by detecting reflected or knocked-off electrons while a

TEM uses transmitted electrons to create an image. SEM is typically used for the

detailed study of the surface of a specimen, while TEM is mainly used for the

internal ultrastructure of cells.

- Check out cellsalive.com! What are the relative sizes of prokaryotic vs. eukaryotic

cells?

Prokaryotic cells range from 0.1-5.0 micrometers in diameter, while eukaryotic

cells range from 10-100 micrometers in diameter.

- What is the smallest size a light microscope can resolve, how about an electron

microscope?

- Smallest size light microscope: 200 nm – the size of a small bacterium

- Smallest size electron microscope: Theoretically can achieve a resolution of

0.002 nm, but the practical limit is 2 nm. This size range includes proteins, lipids,

small molecules, and atoms.

- Why is cell size kept small? Surface area vs. volume ratio.

Cells are kept small due to the surface area and volume ratio. If the ratio

becomes unbalanced, then the cell will not be able to function and perform its

job(s). For example, if the volume increases, the cell will reach a point where it

- Prokaryotes vs. Eukaryotes. What are the similarities? What are the differences?

Provide an example.

In prokaryotes, the DNA is concentrated in the nucleoid and there is no

membrane that separates this region from the rest of the cell. On the other hand,

eukaryotes have a true nucleus that is bounded by a membranous nuclear

envelope. Prokaryotes have circular DNA while eukaryotes have linear DNA.

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Prokaryotes are smaller than eukaryotes, and also lack membrane-bound

organelles. Prokaryotes can be found in the domains Bacteria and Archaea,

while eukaryotes can be found in protists, fungi, animals, and plants.

- Know the basic structure and functions of the following eukaryotic cell organelles –

Do prokaryotes have any organelles?

Prokaryotes do not have any organelles.

- Ribosome structure. Difference between location and function of Bound vs. Free

Ribosomes

Ribosomes are packets of RNA and protein that play a crucial role in both

prokaryotic and eukaryotic cells and are the site of protein synthesis. There are

two parts: a large subunit and a small subunit. Bound ribosomes are attached to

the rough endoplasmic reticulum, whereas free ribosomes are not.

- Nucleus. What is the structure of all the parts of the nucleus? Explain DNA

compaction and DNA vs. Chromatin vs. Chromosomes.

The nucleus has an enclosed double membrane and communicates with the

cytosol via nuclear pores. Within each nucleus is nuclear chromatin that

contains the organism’s genome. Genes within the chromatin are made of DNA.

When a cell is dividing, the nuclear chromatin condenses into chromosomes.

- What are the organelles (and function) of the Endomembrane System?

- ER structure and functions (Rough vs. Smooth)

The ER is a vast network of membrane-bound vesicles and tubules. The

smooth ER, which lacks ribosomes, is responsible for lipid and steroid synthesis, the

breakdown of lipid-soluble toxins, and the control of calcium release in muscle contraction.

The rough ER, which has ribosomes, is responsible for protein synthesis.

- The Golgi structure and function

The Golgi apparatus is a membrane-bound structure with a single

membrane. It functions to package macromolecules for transport elsewhere in

the cell.

- Lysosomes. What are the various functions of the lysosomes? How do

lysosomal enzymes work? How are they kept active in a cell?

Lysosomes contain hydrolytic enzymes necessary for intracellular digestion. The

enzymes break down complex molecules that can include sugars and proteins.

They are kept active in a cell by maintaining an acidic environment.

- Vesicles and Vacuoles and their diverse functions.

Vesicles help package cell secretions at the Golgi apparatus and then transport

this to the cell surface for release. Vacuoles are membrane-bound sacs that plays

roles in intracellular digestion and the release of cellular waste products.

- What are the non-endomembrane system organelles?

The non-endomembrane system organelles include mitochondria,

chloroplasts, and peroxisomes.

- What is the structure and function of Mitochondria?

The structure of mitochondria includes two membranes – an outer

membrane that covers the organelle and contains it like a skin and an inner

membrane that folds over many times and creates layered structures (cristae).

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VC BSC 1010c Foxson STUDY GUIDE – Exam 2– Covers Chapters 6-10 A tour through the Cell (Chapter 6) - - - - - - The discovery of what instrument allowed for the discovery of cells? Microscope Who is credited with discovering the first microscope and coining the term “cell”? Robert Hooke In general, how do microscopes function? What are the differences between how light and electron microscopes work? Microscopes function by passing light or a beam of electrons through a specimen and then through glass lenses. A light microscope involves visible light being passed through the specimen and then through the glass lenses, and the glass lenses refract the light in a way that magnifies the image of the specimen as it is projected into the eye. Electron microscopes involves a beam of electrons being passed through the specimen or onto its surface instead of light. What are differences in how a TEM and SEM function? A SEM creates an image by detecting reflected or knocked-off electrons while a TEM uses transmitted electrons to create an image. SEM is typically used for the detailed study of the surface of a specimen, while TEM is mainly used for the internal ultrastructure of cells. Check out cellsalive.com! What are the relative sizes of prokaryotic vs. eukaryotic cells? Prokaryotic cells range from 0.1-5.0 micrometers in diameter, while eukaryotic cells range from 10-100 micrometers in diameter. What is the smallest size a light microscope can resolve, how about an ele ...
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Tags: biology meiosis chromosomes Mitosis and The Cell Cycle Robert Hooke