2 - Cells & Organelles Flashcards
What is a cell?
The basic structural and functional unit of all living things
What are 4 functional characteristics of a cell?
1) Cell metabolism & energy use
2) Synthesis of molecules
3) Communication
4) Reproduction and inheritance
What is the “cell metabolism and energy use” functional characteristic of a cell?
The ability to use an energy source (e.g. oxygen, glucose, water) to produce substances (e.g. energy, antibodies, hormones)
What is the “synthesis of molecules” functional characteristic of a cell?
The ability to produce molecules, em.g
RNA
Receptors
Proteins
ATP
Amino acids
What is the “communication” functional characteristic of a cell?
Ability to communicate with other cells & with surroundings
Send/receive chemical or electrical signal
What is the “reproduction and inheritance” functional characteristic of a cell?
Ability to undergo mitosis or meiosis.
Genetic information is passed down to future cells during reproduction
What are organelles?
What determines the abundance of a particular type of organelle in a cell?
Small, specialised structures within a cell which have particular functions.
Depends on the cell’s function
What are some examples of major organelles?
(11 examples listed)
Plasma membrane
Cytoplasm
Nucleus
Ribosomes
Golgi apparatus
Lysosomes
Mitochondria
Centrioles
Cilia, microvilli
What is the structure of the plasma membrane?
Phospholipid bilayer in a fluid mosaic model.
Also contains cholesterol, carbohydrates, and proteins.
What are the two components of cytoplasm?
Cytosol
Cytoskeleton
What is the cytosol? What is it made up of? What is it used for?
Fluid part of cytoplasm.
Made up of ions & proteins in water.
Used as energy source
What does the cytoskeleton do?
Supports cells and organs, moves organelles and cell.
What are the 3 components of the nucleus?
Nuclear envelope - porous bilayer
Nucleoplasm
Nucleolus
What is the function of the nucleus?
To contain DNA, which carries the code for the structural and functional characteristics of the cell.
What does the nucleolus produce?
Mainly ribosomes, used for protein synthesis
What are ribosomes?
Sites for protein synthesis. Can be free-floating, or membrane-bound & attached to endoplasmic reticulum.
What is the endoplasmic reticulum? What is the difference between rough and smooth endoplasmic reticulum?
Flattened, interconnecting sacs and tubules.
Rough endoplasmic reticulum has ribosomes attached.
What occurs in the rough endoplasmic reticulum?
Synthesis and modification of proteins
What occurs in the smooth endoplasmic reticulum?
Site of lipid, steroid & carbohydrate synthesis
Detoxifies harmful substances
Breaks down glycogen into glucose
What is the golgi apparatus? What does it do?
Flattened membranous sacs with cisternae (secretory vesicles)
Modified, packages and distributes proteins and lipids which were made in the rough ER
What are lysosomes? Where are they formed? What is their function?
Membrane-bound vesicles containing enzymes.
Formed at golgi apparatus
Digest molecules no longer needed by the cell - fuse with the molecule and digestive enzymes break down the molecule.
What is the mitochondria? What occurs in it?
Organelle with own DNA, site of krebs cycle and electron transport chain.
Produces ATP.
What are centrioles? What do they do?
Barrel-shaped organelles, positioned at right-angles to each other.
Help pull cells apart in cell division.
What are cilia? What do they do? What is an example of the location of cilia?
Whip-like cellular extension on outer surface of some cells.
Move substances across the surface of the cell.
E.g. location: respiratory tract
