Eukaryotic and Prokaryotic Cells Flashcards
(19 cards)
Main features and functions of a cell-surface membrane
Features: Membrane found around the outside of a cell. Made up of lipids and proteins.
Functions: Controls passages of substances in and out of cell
Main features and functions of nucleus
Features: Largest organelle in cell, surrounded by nuclear envelope consisting of 2 membranes. Envelope has many nuclear pores
Function: Contains DNA, holds genetic info necessary for controlling cell
Main features and functions of mitochondria
Features: Oval shaped organelle, enclosed by 2 membrane layers. Inner membrane is folded into a structure called cristae.
Function: Produces ATP for respiration, source of energy for cellular activity.
Main features and functions of lysosome
Features: Organelle containing digestive enzymes called lysozymes. Enzymes separated from rest of cell by lysosome membrane
Functions: Digests unwanted material
Main features and functions of ribosome
Features: Very small organelle, not membrane-bound
Functions: Assembles proteins from amino acids
Main features and functions of rough endoplasmic reticulum
Features: Made of membranes that form a series of tubes in cytoplasm of cell. Membranes covered in ribosomes.
Functions: Synthesises and transports proteins around cells.
Main features and functions of smooth endoplasmic reticulum
Features: Similar to R.E.R, but don’t have ribosomes
Functions: Synthesises lipids
Main features and functions of Golgi apparatus
Features: Stack of flattened sacs, each surrounded by a membrane. Vesicles continually pinched off from ends of sacs
Functions: Packages and processes molecules like proteins for use in and out of cell. Forms lysosomes.
Main features and functions of chloroplasts (plants and algae)
Features: Enclosed by 2 membranes, contains chlorophyll to absorb sunlight.
Functions: Chlorophyll absorbs light energy for photosynthesis to take place.
Main features and functions of cell wall (cellulose)- (plants only)
Features: Made of cellulose, in layered structures, freely permeable (doesn’t affect entrance and exit of substances).
Functions: To keep cells turgid
Prokaryotes vs. Eukaryotes- organelles
Prokaryotes- Do not contain membrane-bound organelles in cytoplasm [pillus, flagella, plasmids)
Eukaryotes- Do contain membrane-bound organelles [golgi apparatus, ER, nucleus, lysosome, mitochondria etc.]
What is the most defining feature of a prokaryotes?
They do not contain a nucleus
What difference is there between ribosomes in eukaryotes and prokaryotes?
Ribosomes in prokaryotes are smaller
What features are sometimes present in prokaryotes?
- Cytoskeleton
- Microtubules
- Flagella
Main functions and features of a nucleoulus
Features: Doesn’t have a membrane, small subspace
Function: Condensed region where ribosomes are formed
What are the steps in cell fractionation?
1) Cut up tissues to remove organelles from cells
2) Use a buffer solution to keep pH constant
3) Blend and liquidate tissue
4) Centrifuge contents
5) Organelles will settle in pellets, smaller density on top, higher density on bottom
In cell fractionation, what is likely to be at the top and bottom?
Low density- top:
- Ribosomes
- Mitochondria
Medium density- middle:
-Chloroplast
High density- bottom:
- Nuclei
- Cell debris
How do you use cell fractionation to isolate a part of a cell from tissue?
- break open cells by cutting and remove debris;
- Solution is cold / isotonic / buffered;
- State where the pellet would be depending on its density
How does a cell with no cell surface membrane maintain its shape?
- Cell unable to change shape;
- (Because) cell has a cell wall;
- (Wall is) rigid / made of peptidoglycan / murein.
