Cells - organelle structures & functions Flashcards
Structure of the plasma membrane.
Phospholipid bilayer.
Proteins embedded in it which are called fluid mosaic.
Structure of mitochondria.
Rod shaped, approximately 1-10um long. Folded to from cristae and the matrix fills up the rest of the space inside (double membrane).
Provides large surface area for attachment of enzymes & proteins for respiration.
Contains protein, lipids, ribosomes & DNA which helps the mitochondrion control the production of its own proteins.
Structure of the rough endoplasmic reticulum.
It’s a series of membrane folds that connect to nuclear envelope.
The space between the folds filled with fluid which encloses a network of tubules a flattened sacs called cisternae.
Studded with ribosomes.
Structure of nucleus.
Largest organelle (10-20um) & has its own membrane called the nuclear envelope.
Nuclear envelope is a double layer. Often have ribosomes attached. Controls entry and exit.
Nuclear pores are gaps in the envelope which allow larger molecules out of the nucleus.
Nucleoplasm is a jelly-like substance which fills the cell.
Nucleus contains the DNA of the cell and is the site of DNA replication.
Structure of cell wall.
Consists of microfibrils of cellulose which allow the cell wall to be flexible as well as strong.
Thin layer called the middle lamella which cement adjacent cells together.
Plant call wall made up of microfibrils of cellulose.
Algae cell wall made up of cellulose or glycoprotein or mixture of both.
Fungi cell wall mixture of Chitin (nitrogen containing polysaccharide), glycan (polysaccharide) & glycoprotein.
Structure of vacuole.
Large vacuole, the membrane around the tonoplast.
It contains water, mineral slats, sugars, amino acids, pigments, waste etc.
It is important in keeping the cell turgid. When it is full it provides support.
Structure of the smooth endoplasmic reticulum.
A series of membrane folds that connect to nuclear envelope.
The space between these folds is filled with fluid, which encloses a network of tubules and flattened sacs called cisternae.
No ribosomes.
Structure of golgi apparatus / body
Appears as flattened sacs (cisternae) that produce vesicles.
The processing department of the cell.
Modifies proteins and lipids are transported in Golgi vesicles which are regularly pinched off from the ends of the Golgi cisternae.
The vesicles move to the cell surface where they fuse with the membrane and releases the contents on the outside.
Structure ribosome.
They float free in the cytoplasm, or they are attached to the endoplasmic reticulum.
The ones found in eukaryotic cells are 25nm whereas the ones in prokaryotic are smaller.
Structure lysosome.
Small and round.
Formed when vesicles produced by the Golgi apparatus contains enzymes such as proteases and lipases.
Structure of chloroplasts.
Surrounded by a double membrane – very selective.
The granum is made up of stacks of up to 100 thylakoids.
Some thylakoids are joined together by tubular extensions.
Provides a large surface area for chlorophyll, enzymes & electron carriers to attach to the membrane.
They contain a light-absorbing pigment (chlorophyll).
The stroma is a fluid filled matrix. It contains several structures including starch grains and enzymes essential for photosynthesis.
Contains DNA so they can make the protein needed for photosynthesis.
Function of mitochondria.
They are the sites for aerobic respiration.
Produce ATP.
More active cells will have more mitochondria.
Function of plasma membrane.
Controls the entry & exit of substances into and out of the cell.
Function of the rough endoplasmic reticulum.
Large surface area for synthesis of proteins & glycoproteins.
Provides a pathway for transport of materials throughout the cell.
Function of cell wall.
Provides mechanical strength to prevent the cell bursting.
Provides mechanical strength to the plant.
Allow water to pass along.
