BCH 201 Introduction to Biochemistry Flashcards
What is a cell?
The structural and functional unit of a living organism
Diameter of eukaryotic cells
5-100 micrometers
The cell can be divided into
Plasma membrane
Cytoplasm
Sub cellular organelles
Discuss the cell membrane
It defines the periphery of the cell and separates the cell contents for the surrounding environment
It is made of a lipid bilayer, embedded with proteins (fluid mosaic model, Nicholson and singer) and a hydrophilic exterior and hydrophobic core
It has a highly selectively permeable membrane to regulate entry and exit of materials e.g membrane transport proteins regulate the influx and efflux of ions and molecules across the membrane
It also contains enzymes involved in metabolism
Discuss the cytoplasm
This is the internal volume of the cell enclosed by the plasma membrane, consisting of aqueous sol. (cystol) and suspended organelles
It’s also contains organic and inorganic molecules, ions enzymes and metabolites
The_and_are solitary whilst other organelles are numerous
Nucleus and Golgi apparatus
Which mammalian cell does not contain a nucleus?
Red blood cell
Functions of the nucleus
The most important organelle
Where DNA and genetic material is stored. The DNA consists of the full set of genes of the organism
Consists of a well-defined membrane called the nuclear envelope
A light portion of the nucleus, the nucleolus, is where RNA synthesis (transcription)
DNA replication occurs in the nucleus
Functions of ER
This is a network of interconnecting membranes enclosing channels or cisternae
Functions of smooth ER
Synthesis of complex lipids and steroids
Function of rough ER
Consists of ribosomes where proteins are synthesized
It is also involved in drug detoxification
Function of mitochondria
spherical, oval, rod-shaped body
power house of the cell where energy is released from the oxidation of food and stored as ATP for metabolic processes
double membrane, inner is folded into cisternae and contains enzymes of the ETC
cytochrome p450 system in mitochondria is involved in steroid synthesis
mitochondria also consists of DNA
difference between genomic and organellar DNA
genomic dna is in the nucleus, double stranded, helical in shape
orgnellar dna is in the mitochondria, double stranded and circular in shape
function of lysosomes
tiny organelles which digest foreign particles
Enzymes in lysosomes cause tissue damage
function of golgi complex
network of flat smooth, membrane and vesicles
It is involved in sorting, packaging, maturation and release of already synthesized protein
types of protein filament
actin-filament
microtubules filament
intermediate filament
What are marker enzymes? Give examples
Enzymes that are specific to the organelle and are found in them only
Examples: Glucose-6 phosphate is found in microsome and lactic dehydrogenase is found in the cytoplasm
function of the capsule in prokaryotes
it is gelatinous in nature and may be a polysaccharide or hyaluronic
the capsule is antigenic and antiphagocytic, it determines the virulence of many bacteria
What is virulence?
Virulence is a pathogen’s or microorganism’s ability to cause damage to a host
Function of flagella
proteinous extrusions through the cell wall, arising from the cytoplasm
they serve as organelles of motility and are also antigenic
function of fimbriae or pili
Hair-like filaments and are also antigenic
Fimbriae are responsible for attachment of bacteria to specific receptors of human cell
