Eukaryotic cells (from power point) Flashcards
What are eukaryotic cells?
Cells that do have a nucleus
What are prokaryotic cells?
Cells that do not have a nucleus
What is an organelle?
Structure within a cell which has a specific function e.g. nucleus, mitochondria
Define ultrastructure?
Structure as seen using an electron microscope.
What is a nucleus?
It contains DNA/ genetic infomation/ genome
Contains instructions for protein synthesis/ controls gene expression.
What is a nucleolus?
Contains RNA
Makes ribosome
What are ribosomes?
Made of 2 subunits
Protein synthesis
On RER for export, loose for proteins for cells use
What is endoplasmic reticulum?
Systems of membranes that form fluid filled sacs (cisternae)
What does the rough endoplasmic reticulum do?
Transports proteins via cisternae.
What does the smooth endoplasmic reticulum do?
Synthesise lipids, cholesterol + steroid hormones.
What is the function of the Golgi apparatus?
Modifies proteins and then packages them into vesicles
What are mitochondria?
Site of aerobic respiration.
Make ATP using glucose
Cells which need a lot of energy contain a lot of them, e.g. sperm cells.
They are self replicating, this means that the have their own DNA.
What are lysosomes?
Contain lysozymes - powerful cell digesting enzyme.
Digests old organelles and foreign matter.
In which cells would lysosomes be abundant?
White blood cells, so they can digest pathogens.
What is the function of the lysosome membrane?
To keep the lysozymes separate from the rest of the cell, so it doesnt digest it.
What are centrioles?
Found just outside the nucleus.
Form spindle fibres to move chromosomes during nuclear division.
What is the structure of cillia and undulipodia?
Contain microtubules in a 9x2 pattern and are surrounded by cell surface membrane.
What do cillia do?
Beat in co-ordinated movements to move substances. Some can contain receptors.
What does undulipodium do?
Enable sperm cells to move.
Describe a cell wall
Made of bundles of cellulose
Provides strength and support, maintains cells shape, contributes to structure and support of whole plant.
Permeable so substances can pass through them.
Describe a chloroplast
Contains chlorophyll for photosynthesis.
Chlorophyll stored in thylakoids which are stacked to form grana.
Which organneles are NOT membrane bound?
Nucleolus, ribosomes, cell wall and centrioles.
Why do some organelles have membranes around them?
Separates contents of organelle from the rest of the cell to form a discrete compartment.
Why would a cell need lots of mitochondria?
If its a very active cell so it needs lots of ATP (energy) e.g. muscle and sperm.
Why would a cell need lots of ribosomes?
Needs to produce lots of protein, e.g. some white blood cells, liver cells.
Why would a cell need lots of lysosomes?
Needs lots of digestive enzymes, e.g. some white blood cells, secretory cells.
Why would a cell need lots of ER and Golgi apparatus?
Needs to produce lots of carbohydrates, fats, protein e.g. liver cells, secretory cells.
Why would a cell need lots of microvilli?
Increase surface area e.g. intestinal epitelial cell.
