Cell Structure 2.1 Flashcards
What is a eukaryote?
A eukaryote is any cell or organism that has a nucleus, examples include plants, animals, fungi and protists
What is the structure and function of the golgi apparatus?
Composed of a stack of membrane bound flattened sacks with secretory vesicles that bring materials to and from
The golgi processes and packages proteins and lipids. It also produces lysosomes. It can also modify proteins.
What is the structure and function of the rough endoplasmic reticulum?
A system of membranes, continuous of the nuclear envelope, containing fluid filled cavities. It is coated with ribosomes
The RER is the intracellular transport system. The cisternae form channels for substances. It is also responsible for protein synthesis for making secretory proteins
What is the cytoplasm?
A gel- like fluid inside the cell that is a medium for chemical reactions
What are ribosomes?
They are the site of protein synthesis, the ribosomes free in the cytoplasm are to make proteins that will be used inside the cell. Ribosomes are formed from equal amounts of protein and rRNA
What is the cell surface membrane?
Made up of a phospholipid bilayer. The cell surface membrane controls the exchange of substances between the internal and external environment of the cell.
What is the structure and function of the smooth endoplasmic reticulum?
This is a system of membranes, continuous with the nuclear envelope containing fluid filled cavities. It does not have ribosomes on the surface
It contains enzymes that catalyse reactions involved in lipid metabolism, for example synthesis of cholesterol/ fats/ phospholipids and steroids.
What is the structure and function of the nucleus?
The nucleus contains chromatin, a complex of DNA and histone proteins. It is the control centre of the cell and stores the organisms genome, transmits genetic information and provides instructions for protein synthesis
What is the nuclear membrane?
The double membrane that surrounds the nucleus. It acts as a barrier and prevents free passage of molecules between the nucleus and the cytoplasm.
What is the nucleolus?
An area inside the nucleus that contains RNA, it does not have a membrane around it. This is where ribosomes are made
What are nuclear pores?
These pores enable larger molecules such as messenger RNA to leave the nucleus and substances such as steroid hormones to enter the nucleus.
What is the structure and function of the mitochrondria?
These can be spherical or rod- shaped and are 2-5 micrometres long. They are surrounded by two membranes with a fluid filled space in between. The inner membrane is highly folded into cristae, it is a fluid filled matrix.
Mitochondria is the site of ATP production during aerobic respiration. They are self replicating and abundant in cells where a lot of metabolic activity takes place
What are lysosomes?
Lysosomes are specialist forms of vesicles that are small bags formed from the golgi apparatus. Each is surrounded by a single membrane. They contain powerful hydrolytic enzymes which can break down waste materiel.
Lysosomes can engulf old cell organelles and foreign matter.
What are cilia and undulipodia?
These are protrusions from the cell and surrounded by the cell surface membrane. They are formed from centrioles.
Cilia act as an antenna and contain receptors that allow the cell to detect information about its immediate environment.
What are centrioles?
Centrioles consist of two cylinder bunches of microtubules at right angles to eachother.
They are used in mitosis and the formation of cilia and undulipodia.
