2.1.1 Cell Structure Flashcards
Give two features of all prokaryotic cells that are not features of eukaryotic cells.
- No membrane bound organelles
- Only have 70s ribosomes
- Peptidoglycan cell wall
Suggest how these properties of the APs allow them to become positioned across the membrane and make a channel through which ions can pass.
- Hydrophobic side next to fatty acids
- Hydrophilic sides allow ion movement/form a channel
Use this information and your knowledge of surface area to volume ratios to suggest an explanation for the position of mitochondria in large U. marinum cells.
- Smaller surface area to volume ratio
- Shorter diffusion pathway when near surface
The organelles labelled X all gave very similar shapes in this cell. Explain why they appear to have different shapes in this drawing.
- Sections are cut at different angles/are in different planes
Which of the following statements is/are true?
Statement 1: Microtubules are part of the 9 + 2 formation in bacterial flagella
Statement 2: Microtubules can be prevented from functioning by a respiratory inhibitor
Statement 3: Microtubules are involved in moving chromosomes from the equator to the poles of the cell during mitosis
Only 2 and 3
The rough endoplasmic reticulum is where the translation of some proteins takes place in a eukaryotic cell. Explain the role of the membrane in the rough endoplasmic reticulum.
- Compartmentalisation
- Separating proteins from the cell cytoplasm
- Holds ribosomes in place
The student used the following procedure to stain the sample:
- Use forceps to place the sample on a glass slide
- Use a pipette to place two drops of the stain in the centre of the sample
- Carefully lower a cover slip onto the sample ensuring that the cover slip is parallel with the slide as it is lowered
What should be altered?
- Cover slip should be lowered at an angle
- Stain should be placed at the edge of the sample
Suggest why goblet cells have large numbers of mitochondria?
To provide lots of ATP
Table 2.1 compares some features of animal cells, plant cells, yeast cells and bacterial cells. Complete the table.
Means of cell division in yeast - budding
Presence of nucleus in yeast - yes
Explain why early eukaryotes were able to grow more quickly than cells that did not possess mitochondria.
- Able to aerobically respire
- Produces more ATP
- ATP needed for active transport/cell division/protein synthesis/DNA replication
- More ATP = faster metabolic processes
Describe three other cellular functions of the cytoskeleton.
- Maintains position of organelles
- Provides support
- Aids movement of molecules/vesicles/organelles within the cell
Peroxisomes are vesicles that usually contain enzymes such as catalase. Explain how peroxisomes can be moved around inside the cell.
- Attach to cytoskeleton
- Moved by motor proteins
Suggest two ways tubulin is essential to protein synthesis and protein secretion in eukaryotic cells.
- Moves mRNA from nucleus to ribosomes
- Moves vesicles containing proteins from golgi apparatus to plasma membrane
Epithelial cells in the airways of mammals play an essential role in defences against pathogens. Explain the function of epithelial cells in the airways of mammals in the defence against pathogens and suggest the importance of the cytoskeleton in carrying out this function.
- Goblet cells secrete mucus
- Mucus traps pathogens
- Phagocytes/neutrophils/macrophages
- Ciliated cells move mucus
- Cytoskeleton move cilia
