Eukaryotic cells: Plants Flashcards
Structure of cell vacuole
- Filled with fluid surrounded by a single membrane (called a tonoplast.)
Function of cell vacuole (3 main functions.)
- Make cells turgid (therefore provide support.)
- Temporary (food) store of amino acids and sugars.
- Pigments (in vacuole) may colour petals, attracting pollinating insects.
True or False
Vacuoles are found in plants, algae and fungi
- FALSE!
- Vacuoles are only found in plants.
Structure of chloroplasts.
- Surrounded by a double membrane.
- Contains thylakoids (folded membranes)
- Fluid filled stroma contains enzymes for photosynthesis.
What are thylakoids (folded membranes in chloroplasts) embedded with?
- Thylakoids are embedded with chlorophyll.
Function of chloroplasts?
- Site of photoynthesis.
True or False
Chloroplasts are only found in plants.
- False!
- Chloroplasts are found in plants AND in algae.
Structure of cell wall.
- In plants, algae and fungi.
- Plants: made of microfibrils of the polysaccharide cellulose.
- Fungi: made of chitin (nitrogen- containing polysaccharide.)
Why is it useful for plant cell walls to specifically have **microfibrils ** of cellulose?
- Microfibrils have strength (contributing to overall strength of cell wall.)
Function of cell wall.
- Provide structural strength to the cell.
True or False
Fungi, plants and algae all have cell walls.
- True.
- Fungi, plants, algae all have cell walls.
What are algae cell walls made of?
- Either cellulose
OR - Glycoproteins
OR - A mixture of both.
Structure of the cell surface membrane.
- Found in all cells.
- Phospholipid bilayer: molecules embeded within and on the outisde (ie. proteins, carbohydrates, cholesterol.)
Function of cell surface membrane
- Controls the entrance and exit of molecules.
What are grana?
- Grana are stacks of thylakoid membranes.
How are chloroplasts adapted to their function of aborbing sunlight and carrying out photosynthesis?
3 main adaptations
1.) Thylakoids provide large surface area for attachment of chlorophyll/ enzymes that carry out first stage of photosynthesis.
2.) Fluid of stroma contains enzymes (needed to make sugars) in 2nd stage of photosynthesis.
3.) Chloroplasts contain their own DNA and ribosomes so they can quickly manufacture proteins needed for photosynthesis (rather than proteins being made out of chloroplasts and slowly being brought to chloroplasts.)
() - extra info for clarification.
Give 4 ways in which DNA in chloroplast is different from DNA in the nucleus.
June 2019 AS Paper 1
- DNA is shorter
- DNA in chloroplast isn’t associated with histones, unlike nuclear DNA.
- DNA in chloroplasts = circular, not linear like nuclear DNA.
- Has fewER genes.
