Cell Structure Flashcards
What is a Tissue?
Collection of similar cells that perform a specific function
What is an Organ?
A combination of coordinated tissues that perform a variety of functions and often have a predominant function.
What is an Organ System?
Organs work together as a single unit known as an organ system. Organs are grouped together to perform functions more effectively.
What is the role of the Nucleus?
Nucleus contains the organisms geneticinformation (DNA) and controls all the activities of the cell.
What does the Nucleus Contain?
-Nuclear envelope: A double membrane that controls the exit and entry of materials and contains the reactions taking place within it.
-Nucleolus: Manufactures ribosomal RNA and assembles the ribosomes.
-Nucleoplasm: jelly like materiel which makes up most of the nucleus.
-Nuclear pores: Allows passage of large molecules e.g. MRNA out of the nucleus.
Ribosome
Site for protein synthesis - Contains a large and small sub unit
- Ribosomes are smaller in prokaryotic cells (70s) than eukaryotic cells (80s)
What is the role of the Mitochondria?
Site of Aerobic respiration, so is responsible for the production of ATP from respiratory substrates to release energy.
What are the structures of the Mitochondria?
Outer and inner membrane (double membrane): controls the the entry and exit of material
Cristae: Provides a large surface area for the attachment of enzymes and other proteins involved in respiration.
Matrix: contains proteins, lipids, ribosomes and DNA to allow mitochondria to produce its own proteins. Contains enzymes involved in respiration too.
Chloroplast
Chloroplast envelope: Double plasma membrane which is highly selective in what it allows to enter and leave the chloroplast.
Grana- (stacks of thylakoids) contains chlorophyll which absorbs sunlight for photosynthesis
Contains both DNA and ribosomes thus can quickly and easily manufacture proteins needed for photosynthesis.
Stroma- responsible for synthesis of sugars (contains starch grains)
Rough Endoplasmic Reticulum
-Has ribosomes on its outer surface
- Provides a large surface for the synthesis of proteins and glycoproteins.
Smooth Endoplasmic Reticulum
Synthesises, stores and transports lipids and carbohydrates
Which Polysaccharide is the cell wall of eukaryotic cells made from?
Cellulose- provides strength in order to prevent it the cell from bursting under the pressure created by an osmotic entry of water
Vacuoles
Fluid filled sac surrounded by a membrane tonoplast
Contains cell sap ( solution of mineral salts, sugars, amino acids, wastes and pigments.)
Sugars and Amino Acids act as a temporary food store.
Golgi Apparatus
Processes, packages and sometimes modifies new proteins and lipids
Golgi Vesicle
Stores the lipids and proteins and transports them to the cell surface membrane
Fuses with the membrane and releases its contents outside (exocytosis).
