2.1.1 Cell structure: Eukaryotes and Prokaryotes Flashcards
What is the function of the nucleus?
Controls cell activities and holds/stores the genetic material of an organism (DNA)
The nucleus has a …
Double membrane
What is the double membrane called (Nucleus)?
Nuclear Envelope
What is in the nucleus?
Nucleolus
Structure of the nuclear envelope?
It has nuclear pores in its walls
It is continuous with the Rough endoplasmic reticulum
What is the function of the nuclear envelope?
Separates the content in the nucleus from the external environment (cytoplasm)
Functions of the pores in the nuclear envelope?
Controls the movement of substances in and out of the nucleus
e.g mRNA for protein synthesis or steroids going in
Function of the nucleolus?
Synthesis/Production of ribosomes
Structure of the nucleolus?
Not membrane-bound
Made from RNA
How is DNA structured?
As Chromatin
Chromatin is?
DNA wound around histone proteins
How is Chromatin usually found as?
Found spread out or extended in the nucleus and only condenses into the chromosome structure before cell division (late prophase)
Chromatin makes up…
the genome of an organism
What is the function of the Rough endoplasmic reticulum?
Facilitates protein synthesis by providing a large surface area for the ribosomes on its surface.
The ribosomes on the RER transport the newly synthesised protein to the Golgi to be modified and packaged
It is a transport system
Structure of the RER:
Has fluid-filled sacs and is a membrane system (cisternae)
Continuous with the Nuclear Envelope
Has Ribosomes on its surface
Function of the SER?
Synthesis of lipids (and some carbs)
Examples of the products synthesised in the SER:
Cholesterol
Steroid Hormones
Structure of SER:
Fluid-like sacs (cisternae)
Structure of Golgi Apparatus?
Fluid-filled membrane-bound flattened sacs with vesicles surrounding them
2 Functions of the Golgi Apparatus?
- Processes and Modifies proteins that have come from the RER and repackages them into vesicles for exocytosis
- Synthesises (Produces) Lysosomes
What are ribosomes made up of?
RNA and proteins
Ribosomes are not…
Membrane-Bound
Function of Ribosomes?
Site of protein Synthesis; translates functional RNA (mRNA) into a polypeptide
Ribosomes can be?
Cytoplasmic
Stuck on RER
Mitochondria function?
Site of ATP production during Aerobic respiration, releasing energy.
Mitochondria can self-replicate to cater to areas with high energy requirements
Mitochondria Structure?
It has a double Membrane with multiple folds called cristae which increases the organelle’s surface area for increased respiration
Lysosomes structure?
Phospholipid rings with hydrolytic enzymes (digestive enzymes) within, that are separate from the cytoplasm
Lysosomes function:
Engulfs and destroys old organelles or foreign waste material using the digestive enzymes
Plasma Membrane consists of?
Phospholipid bilayer and proteins within and between the layer
Has cholesterol
Function of Plasma Membrane?
Controls the movement of substance in and out of the cell surface membrane
Cholesterol regulates the fluidity of the cholesterol
Holds the cell and its content together in a cell
Centrioles Structure?
Bundles of microtubules in a 9+2 structure (with motor proteins for mobility) which form spindle fibres.
Centrioles function?
The spindle Fibres pull apart the sister chromatids (anaphase) during mitosis
They also form cilia and flagellum
Chloroplast Function:
Site of photosynthesis
Chloroplast Structure:
Has a double membrane where chlorophyll is held in thylakoids
These thylakoids are stacked into Grana
Lamellae link together the Grana
Cell Wall function and structure:
Function: Supports and strengthens the cell
Structure: Rigid and tough
The plant cell wall is made up of the polysaccharide…
Cellulose
The Fungi cell wall is made up of the polysaccharide…
Chitin
The Bacteria cell wall is made up of the polysaccharide…
Peptidoglycan
The Prokaryotes cell wall is made up of the polysaccharide…
Murein
Vacuole structure and function:
Structure: Contains cell sap, proteins and extra nutrients
Function: Keeps cell turgid
What is flagella?
A tail-like projection that contains a bundle of microtubules with motor proteins) which allows it to move and propel itself
Found of sperm cells
Cilia?
Hair like projections found on the surface of cells
Has bundles of microtubules and can be found in the trachea and small intestine
