Eukaryotic Cells Flashcards
Define the terms eukaryotic and prokaryotic cells
Eukaryotic cells:
Cells that have DNA contained in nucleus, containing membrane bound specialised organelles
Examples of eukaryotic cells include plant and animal cells
Prokaryotic cells:
Cells that have DNA free in the cytoplasm, with no organelles.
Examples of prokaryotic cells inlude bacteria and archaea
Outline the structure of the nucleus:
The nucleus is surrounded by the nuclear envelope, a semi permeable double membrane
Nuclear pores on the surface to allow substances to enter/exit
There is a dense nucleolus made of RNA and is the site of rRNA synthesis
What is the function of the nucleus:
The nucleus is where DNA is replicated, being the site of mRNA transcription. It also contains the genetic code of each cell
Outline the structure of the mitochondria:
The mitochondria is surrounded by a double membrane made up of the inner and outer membrane.
The inner membrane is folded to form cristae being the site of electron transport chain
The fluid centre is the mitochondrial matrix containing loops of DNA, lipids, proteins etc
What is the function of the mitochondria?
The mitochondria is the site of aerobic respiration to produce a lot of ATP
Outline the structure of chloroplast:
Chloroplast are surrounded by a double membrane, consisting of a inner and outer membrane.
They contain folded membranes embedded with pigment called thylakoids. The thylakoid membranes are stacked up to create granum (one stack = grana)
There is fluid inside the organelle called strong containing enzymes for photosynthesis
They are found in plants
What is the function of chloroplasts?
Chloroplasts are the site of photosynthesis for converting solar energy to chemical energy
Outline the structure of the Golgi apparatus
The Golgi apparatus consists of stacks of membranes that make up flattened sacs (cisternae) with small rounded hollow structures called vesicles
What is the function of the Golgi apparatus?
The Golgi apparatus is where proteins are processed, packaged and modified for export and synthesises glycoproteins
Outline the structure of a lysosome
Lysosomes are sacs surrounded by a single membrane containing digestive enzymes
What is the function of a lysosome?
A lysosome can hydrolyse phagocytic cells, digest worn out organelles for reuse of materials and perform the exocytosis of digestive enzymes
Outline the structure of ribosomes
Ribosomes are small organelles made up of two subunits of protein and rRNA. They are either free in cytoplasm or attached to the endoplasmic reticulum
What is the function of ribosomes?
Ribosomes are the site of protein synthesis
Outline the structure of the endoplasmic reticulum
The endoplasmic reticulum is a network of folded membranes called cisternae. There are two types roughly endoplasmic reticulum and smooth endoplasmic reticulum.
What are the key differences between rough and smooth endoplasmic reticulum?
Rough endoplasmic reticulum has ribosomes on the cisternae allowing protein synthesis to occur
Smooth endoplasmic reticulum has no ribosomes but stores lipids and carbohydrates, synthesising lipids
Outline the structure of the cell wall for bacteria and plants
Bacteria has a cell wall made of the polysaccharide murein
Plants have a cell wall made of the polymer cellulose’s microfibrils
What is the function of the cell wall?
The cell wall provided mechanical strength and support. It acts as a physical barrier against pathogens.
What is the function of the cell wall?
The cell wall provided mechanical strength and support. It acts as a physical barrier against pathogens.
Outline the structure of the cell vacuole in plants
The cell vacuole is filled with fluid surrounded by a single membrane called the tonoplast
What is the function of the cell vacuole in plants?
The cell vacuole makes cells turgid, providing support. Acts as an temporary store of sugars and amino acids
What cells have cell walls?
Plant and fungi cells have cell walls
What is the cell wall of a plant cell made up of?
In plants, the cell wall is made of microfibrils of the cellulose polymer
What is the cell wall of a fungi cell made up of?
In fungi cells, the cell wall is made up of chitin, a nitrogen containing polysaccharide
What is chitin?
Chitin is a nitrogen containing polsaccharide,
What is the function of the cell wall?
The cell wall provides structura; strength for the cell
What is he function of the plasma membrane?
The function of plasma membrane is to control the movement in and out of molecules
Where is plasma membrane found on cells?
Plasma membrane is found on the outside of all cells
Explain some common cell adaptations (3pts)
- Cells have folded membranes or microvillis to increase the surface area to improve diffusion
- Cells have many mitochondria to allow for the production of large amounts of ATP for active transport
- Cells have walls that are one cell thick to reduce the distance of the diffusion pathway
What is the function of the nuclear pores? Example of this function?
To allow the exchange of substances between the nucleus and cytoplasm. For example ribosomes will leave the nucleus and nutrients/hormones will enter
Where are chromosomes found ? What state are they in?
Chromosomes are found in the nucleus in a loosely coiled state
What does the nucleolus make?
The nucleolus manafactures ribosomes
