Cell Structures and Functions Flashcards
Plasma Membrane
Structure and Function of Components:
Phospholipid Bilayer (2)
Proteins (6)
Membrane Carbohydrates (2)
Glycocalyx Functions (6)
General Plasma Membrane Functions (4)
Phospholipid Bilayer:
Hydrophilic heads
Hydrophobic tails
Provides semipermeable barrier
Integral and Peripheral Proteins:
stabilisers- anchor
identifiers- recognise
carriers- transport solutes
channels- water and solutes
enzymes- catalyse reactions
receptors-bind to ligands
Carbohydrates:
glycoproteins/glycolipids
Extends beyond cell membrane to form glycocalyx:
Glycocalyx:
binding, anchoring, lubrication, locomotion, protection, recognition
General Functions:
Barrier
Controls Exchange
Sensitive to Environment
Structural Support
Cytoplasm:
Cytosol
Cytoskeleton (3)
Organelles
Inclusions
Cytosol- fluid with dissolved materials
(eg. nutrients, ions, waste)
Cytoskeleton- provides structure
+microfilaments- strength, consistency of cytosol
+intermediate filaments- strength, maintain cell shape/position of organelles/cell position
+ microtubules- attach to centrosome, change cell shape, move organelles in the cell, form centrioles/spindles
Organelles- sites/structures with specific functions
Inclusions: insoluble materials
(eg. glycogen/lipid droplets)
Microvilli
Structure:
Small finger like extensions attached to cytoskeleton
Function:
increase surface area for absorption
Cilia
Primary and Motile Functions
Structure:
Long whiplike extensions
Primary Function:
Sensor
Motile Function:
Move materials over cell surface using power and return strokes
Centrioles (within Centrosome)
Structure:
Paired cylinders made of microtubule triplets located in centrosome near the nucleus
Function:
form spindle apparatus during cell division
Proteasomes
Structure:
Hollow cylinders with enzymes
Function:
Breakdown of proteins
Ribosomes
Structure:
RNA/Proteins
Small and Large Ribosomal Subunits
Fixed/Bound to RER or Free in Cytoplasm
Function:
Protein Synthesis
Golgi Apparatus
Structure:
Stacked flattened membranes with storage chambers
Functions:
Storage, alteration, packaging of secretory products and lysosomal enzymes
Mitochondria
Structure:
Smooth outer membrane with inner membrane folds (cristae) with metabolic enzymes
Functions:
Produces ATP
Rough Endoplasmic Reticulum
Structure:
Network of membranous channels with Ribosomes
Function:
Modifies and packages synthesised proteins
Smooth Endoplasmic Reticulum
Structure:
Network of membranous channels: No Ribosomes
Functions:
+Synthesises Lipids and Carbohydrates
(eg. phospholipids, cholesterol, steroid hormones, glycerides, glycogen)
+Detoxification of drugs and toxins
Peroxisomes
Structure:
Vesicles with enzymes
Functions:
breakdown/catabolise fats or toxic compounds
Lysosomes
Primary and Secondary
Vesicles with enzymes:
Primary- inactive enzymes
Secondary- activated enzymes (after fusing with damaged materials)
Functions:
recycles damaged organelles
destroys pathogens/bacteria/molecules
Nucleus
Structure:
Nuclear Envelope (double walled) with Pores
Nucleoplasm
Nucleoli
Functions:
Contains DNA (chromatin or chromosomes)
Controls structure and function of cell:
metabolism, storage, processing of genetic information and protein synthesis
Nucleolus
Structure:
Small, centred in nucleus
Function:
site of rRNA synthesis and assembly of ribosomal subunits
