Chapter 2. Basic Components Of Living Systems Flashcards
What are the two fundamental types of cells?
Prokaryotic and Eukaryotic
What is a prokaryotic cell?
They are single-celled organisms with a simple structure of just a undivided internal area called the cytoplasm
What do eukaryotic cells make up?
A eukaryotic cell makes up multicellular organisms. Such as animals,plants and fungi.
What is a eukaryotic cells internal structure?
Eukaryotic cells contain a membrane noun nucleus (nucleoplasm) and cytoplasm
What divides the cytoplasm into different membrane-bound compartments?
Organelles
How permeable are membranes?
Membranes are partially permeable
Where is DNA contained?
DNA is contained within a double membrane called the nuclear envelope
How is RNA exported?
Through the digital pores
What does DNA associate with to form chromatin?
Histones
What does chromatin form?
Chromosomes
Where is the nucleolus found?
In the nucleus
What is the nucleolus responsible for?
It is responsible for the production of ribsomes
What is the amount of mitochondria in a cell a reflection of?
The amount of energy it uses
What is mitochondria?
It is the site of the last stages of cellular respiration.
What type of membrane does mitochondria have?
A double membrane
What is folded to form cistae?
The inner membrane in mitochondria
What is the matrix?
The fluid interior of the inner membrane of the mitochondria
What does the membrane forming cistae contain?
The enzymes used in mitochondria
What are vesicles?
They are membranous sacs that have storage and transport roles
What do vesicles consist of?
They consist of a single membrane with fluid inside
What are lysosomes?
They are specialised forms of vesicles that contain hydrolytic enzymes.
What are are lysosomes responsible for?
Breaking down waste material in cells including old organelles
What are responsible for breaking down pathogens ingested by phagocytise cells?
Lysosomes
Where is the cytoskeleton present?
Throughout the cytoplasm of all eukaryotic cells
What is the cytoskeleton necessary for?
The shape and stability of a cell
What are the cytoskeletons 3 components?
- Microfilaments
- Microtubules
- Intermediate fibres
What are microfilaments?
They are contractile fibres that are formed from the protein actin.
What are microfilaments responsible for?
The cell movement and the cell contraction during cytokinesis - the process in which the cytoplasm of a single eukaryotic cell is divided to form two daughter cells.
What are microtubulin?
Globular tubulin proteins polymerised to form tubes that are used to determine the shape of the cell
What tracks the movement of organelles around the eukaryotic cell?
Microtubules
What are intermediate fibres?
Fibres that give mechanical strength to cells and help maintain their integrity
What are centrioles composed of?
Microtubules
What do two centrioles form?
The centrosome, which is involved in the assembly and organisation of the spindle fibres during cell division.
Why is flagella used in cells?
To enable motility, or in some cells used as a sensory organelle detecting chemical changes in the cells environment
What are the two different types of cilia?
- Mobile
- Stationary
What is stationary cilia?
It is present on the surface of many cells and has an important function in sensory organs such as the nose
What is mobile cilia?
It causes fluids of object adjacent to the cell to move by the cilia beating in a rhythmic manner creating a current
What structure does each cilium have?
Each cilium contains two central microtubules surrounded by nine pairs of microtubules. This is known as a 9+2 arrangement.?
How is the beating motion in cilia caused?
By pairs of parallel microtubules sliding over each other
Why is it important to synthesise proteins?
For internal use and for secretion (transport out of the cell)
What is the endoplasmic reticulum?
A network of membranes enclosing flatted sacs called cisterns.
What is the endoplasmic reticulum connected to?
The outer membrane of the nucleus
What are the two types of endoplasmic reticulum?
Smooth and Rough
What is the smooth ER responsible for?
Lipid and carbohydrate synthesis and storage
What does the rough ER have bound to it?
Ribosomes
What is the rough ER responsible for?
The synthesis and transport of proteins
What are ribosome constructed of?
RNA molecules made in the nucleolus of the cell
What process are ribosomes the site of?
Protein synthesis
Where else can you find ribosomes?
In the mitochondria, chloroplast and prokaryotic cells
What is the Golgi apparatus formed of?
Cisternae- does no contain ribosomes
What is the Golgi apparatus’ role?
Modifying proteins and ‘packing’ then into vesicles.’
What is the Kane difference between plant and animal cells?
Plant cells are ridged, they have a cell wall surrounding the cell-surface membrane
What substance are plant cells made up of?
Cellulose - a complex carbohydrate
How permeable are plant cells?
Freely permeable
What are vacuoles?
Vacuoles are found in plant cells and are membranes lined sacs in the cytoplasm containing cell sap
What are permanent vacuoles important in the maintenance of?
Tutor
What is the membrane in a vacuole called?
Tonoplast
How permeable is tonoplast?
Partially permeable
If vacuoles appear in animal cells how permanent are they?
They are small and transient - not permanent
What are chloroplasts responsible for in plant cells?
Photosynthesis
Where are chloroplasts found in plants?
In the cells in the green parts such as the leaves and stems - not the roots
What type of membranes does chloroplasts have?
Double membrane
What is the fluid enclosed in chloroplasts called?
Storms
What are thylakoids?
They are an internal network of membranes, that are flattened sacs found in chloroplast
What are several thylakoids stacked together called?
Granum
What is the grana joined by membranes called?
Lamella
What does the grana contain?
Chlorophyll, where light-dependent reactions occur during photosynthesis
Why is chloroplast and mitochondria similar?
They both contain DNA and ribosomes - which enables them to make their own proteins
Are prokaryotic organisms multi cellular or unicellular?
Unicellular
How many molecules of DNA does prokaryotic cells usually have?
One - a chromosome
How big are the ribosomomes in prokaryotic cells compared to those in eukaryotic cells?
They are smaller than those in eukaryotic cells
What are prokaryotic cells cell wall made of?
Peptidoglycan (murein)
Does the flagella in prokaryotic cells have a 9+2 structure?
No
What process supplies the energy to rotate the filament that forms the flagellum in prokaryotic cells?
Chemiosmosis
What is the flagellum attached to the cell membrane of a bacterium by in prokaryotic cells?
By a basal body and rotated by a molecular motor
