Understanding Eukaryotic & Prokaryotic Cells: Cell Biology & Microscopy, Study notes of Cell Biology

Download Understanding Eukaryotic & Prokaryotic Cells: Cell Biology & Microscopy and more Study notes Cell Biology in PDF only on Docsity!

Learning List

1. Eukaryotic cells (plant and animal cells) have a cell

membrane, cytoplasm and genetic material enclosed in a

nucleus.

2. Prokaryotic cells contain cytoplasm, cell membrane and a

cell wall. The genetic material is not in a nucleus but a single

loop.

3. Prokaryotic cells can contain plasmids.

4. Prokaryotic cells are much smaller than eukaryotic cells.

5. Animal cells contain nucleus, cytoplasm, cell membrane,

mitochondria and ribosomes.

6. Plant cells also contain chloroplasts, a vacuole and a cell

wall.

7. Plant cell walls are made of cellulose.

8. Most animal cells differentiate at an early stage (become

specialised)

9. Most plant cells retain the ability to differentiate throughout

their life.

10. Cells can be specialised to carry out a particular

function e.g. sperm cells, nerve cells, muscle cells, root hair

cells, xylem and phloem cells.

Cells

All living things are made of ________________. Cells can either be ____________________ or ________________________. Plants and animal cells are _________________________. Label the diagram of a plant and animal cell. Compare the structure of a plant and animal cell Bacteria are _______________________ cells. Label the diagram of a bacterial cell.

Complete the Venn Diagram to compare eukaryotic and prokaryotic cells Function of cell organelles Prokaryotic Eukaryotic

Learning List – Microscopes

1. Light microscopes use light and lenses to form an image of a

specimen.

2. Light microscopes are used to se nuclei, chloroplasts, cell

wall, cell membrane and mitochondria. Electron

microscopes use electrons to form an image.

3. Stains are used to make the specimen visible.

4. Electron microscopes have a higher magnification.

5. Electron microscopes has a higher resolution (able to

distinguish between 2 points, gives a sharper image).

6. Electron microscopes allow us to see ribosomes and

plasmids.

7. The specimen has to be dead when using an electron

microscope.

8. Magnification = Image Size ÷ Actual size

9. 1000μm = 1mm

10. We can use standard form to represent the size of a

specimen eg 0.025 = 2.5 x 10

• 2

mm

Microscopes

Put these things into size order, starting with the largest: Ribosome Chloroplast Nucleus Mitochondria Eukaryotic cell Plasmid Prokaryotic cell Identify the organelles which can be seen with a light microscope. Identify the organelles which can only be seen with an electron microscope Explain why an electron microscope is needed to see these organelles.

Magnification

1mm = ___________ μm

Magnification = Image size

Actual size

Convert these mm to μm

1. 4 =
2. 8 =
3. 12 =
4. 0.2 =
5. 0.05 =
6. 1.7 =
7. 3.58 =
8. 0.003 = Convert these μm to mm 1. 7000 = 2. 450 = 3. 20 = 4. 3 = 5. 0.5 = 6. 65 = 7. 400 000 = 8. 12 500 =

1. A specimen is 50 μm wide. Calculate the width of the image of the specimen using a microscope with a magnification of x500. Give your answer in mm.
2. An onion cell is viewed under the microscope. The image of the cell is 7.5mm wide. The magnification of the microscope is x100. Calculate the real size of the cell.
3. Underneath the microscope, a cell appears to be 40mm wide. The actual width of the cell is only 4μm. Calculate the magnification of the microscope.

Specialised cells

1. Match the specialised cell with its feature. Sperm cell Contain dendrites (extensions) that connect to other cells. Nerve cell Has a long tail for movement and many mitochondria to release energy for this. Muscle cell Contain proteins that slide over each other making fibres contract and many mitochondria to release energy for this. Root hair cell Cell wall broken down to produce sieve plates which allow water carrying dissolved substances such as glucose to move freely up and down. Supported by companion cells which contain mitochondria needed for the movement of substances. Phloem cell Hollow tubes containing lignin to^ allow water to move freely through them. Lignin helps them withstand the pressure of moving water up the stem. Xylem cell Contain many chloroplasts which are needed to absorb light energy for photosynthesis. Palisade (leaf) cell Has extensions which increase the surface area for the absorption of water. Contain many mitochondria for the uptake of ions by active transport

Learning List – Diffusion, Osmosis and Active Transport

1. Diffusion is the movement of particles from an area of

higher concentration to an area of lower concentration.

2. Diffusion happens in liquids and gases.

3. Diffusion does not require energy.

4. The rate of diffusion is affected by the concentration

gradient, temperature and surface area of the membrane.

5. Osmosis is the movement of water molecules from an area

of higher concentration (dilute solution) to an area of lower

concentration (concentrated solution) across a partially

permeable membrane.

6. Osmosis does not require energy.

7. Cells that gain water by osmosis get bigger and can burst.

8. Cells that lose water by osmosis get smaller.

9. Active transport is the movement of substances from an

area of lower concentration (more dilute solution) to an

area of higher concentration (concentrated solution).

10. Active transport required energy from respiration.

Higher concentration of water Lower concentration of water

Diffusion

Diffusion is the ____________ movement of particles from and area of ___________ concentration to an area of ____________ concentration. The factors that affect the rate of diffusion are: Suggested revision task to complete:  Create a series of flash cards showing different examples of where diffusion happens. Here are some ideas to get you started: o Movement of oxygen from red blood cells into muscle cells o Movement of oxygen from alveoli into blood capillaries and the movement of carbon dioxide from the blood capillaries into the alveoli o Movement of glucose from the small intestines into the blood capillaries o Movement of glucose from the blood capillaries into the muscle cells o Movement of carbon dioxide from the air into a leaf through the stomata and the movement of oxygen out of the leaf through the stomata o Movement of oxygen from water into the blood capillaries of the gills of a fish For each cell describe which way the oxygen will move and explain why.

Osmosis

Osmosis is the movement of ____________ molecules from a region of ______________ water ______________ to a region of _____________ water potential across a ___________________ ________________ ________________. Describe and explain the results shown below. Active transport Active transport is the movement of particles _________________ a concentration gradient i.e. from an area of ____________________ concentration to and area of ______________________ concentration using __________________- transferred during ________________________.

Examples of active transport

 Absorption of mineral ions by root hair cells  Absorption of glucose in the small intestine (Most soluble food are absorbed by diffusion however when the concentration of glucose in the blood is higher than in the small intestine active transport is used)  Reabsorption of glucose and ions in the kidney.

Diffusion, Osmosis or Active transport?