Module 1 - Topic 1-2: Cell Structure Flashcards
Cytology
Study of cells
Histology
Study of tissue
Human structure
Atoms- molecules- cells- tissues- organs- system- the organism
Homeostasis
State of balance within the body
Homeostasis of body fluids
Separation of the fluid compartment
Compositions of the fluid change as substances move between compartment
Intercellular fluid
Between cells
Intracellular fluid
Within cells
Extracellular fluid
Outside cells
Negative feedback
Response is generated in order to switch off or reduce the source of a given stimulus
Positive feedback
Intensify or increase the level of stimulus
Epithelial tissue
Skin and Tract lining, outside body
Connective tissue
Bone, cartilage and blood
Nervous tissue
Variety of nerves
Muscular tissue
Skeletal, smooth and cardiac muscle
Polar head of phospholipid
Hydrophilic
Fatty acid tails of phospholipid
Hydrophobic
Cell membrane - function
Separates/ protects the inside of the cell from external wnvironment
- detects external environmental changes
- cell to cell communication
- temp and pressure changes
Lipid bilayer - function
Forms barrier to entry or exit of polar substances
Lipid bilayer - makeup
Two back to back layers of 3 types of lipid molecules
- double row of phospholipid molecules
- scattered cholesterol and glycolipid molecules
Phospholipids
75% of cell membrane lipids
- each molecule is amphipathic (polar and nonpolar)
Lipid bilayer - permability
Permeable to water, non polar molecules
Iimpermeable to polar and charged molecules, ions
Transmembrane proteins
Specific channels
- used for small and medium polar molecules
Macromolecules
- large proteins
- unable to pass through cell membrane so uses other transport
Cholesterol
Allows lipid bilayer to be malleable
Prevent rigidness
Maintains cell fluidity
Transporter proteins
Bonds specific substances to transport through lipid bilayer
Receptor proteins
Cellular recognition site
Bonds to signalling molecule
Cell identity marker
Allows cell to recognise other similar cells
Linker proteins
Anchors cells together
Allows cell movement
Holds cell shape
Enzyme
Catalysed chemical reactions
Mediated transport
Moves material with help of transport protein
Non mediated protein
Doesn’t use transport Protein
Passive transport
Moves substances down concentration gradient
Active transport
Uses energy atp to drive substances against concentration gradient
Vesicular transport
Moves large materials across membrane in small vesicles
Endocytosis
Moves into cell
Exocytosis
Moves out of cell
Simple tissue
Cells are all the same structure
Compound tissue
Mixture of cells with different functions
Living organism criteria
Metabolism Responsiveness Movement Growth Differentiation Reproduction
Inner region of membrane
Highly insoluble as it is made up of hydrophobic tails
Integral membrane proteins
Proteins inserted between phospholipid molecules
Peripheral proteins
Attached to either inner or outer surface
Glycoproteins and glycolipids
Proteins and phospholipids that have carb molecules attached to them
Function as cell signalling and cell receptors
Channel proteins
Allows specific substances to move through pores
Signal transduction
Stimulation of plasma membrane protein by external stimulus
Passive transport
Diffusion through bilayer
Diffusion through channel
Facilitated diffusion
Actin Cortex
Dense network of protein below surface of plasma
Linked to plasma membrane via integral proteins
Actin
Property of polymerising within the cell to produce supportive cytoskeleton
Intermediate filaments
Tough, rope like fibrous proteins
Microtubules
Composed of Tubulin subunits
Microfilament
Thin
Filament location
Actin microfilaments - plasma membrane
Microtubules - central portion of cell
Intermediate filament- central portion of cell
Cytoskeleton
Constantly changes to meet requirements of cell
Facilitates transport of cellular component by interacting with motor proteins
Microvilli
Small finger like projections that increase surface area
Supported by actin microfilaments and are found on cells that absorb
Cilia
Motile structures
Present in variety of cells
Transport substances along surfaces of cells
Flagella
Found in male sperm
Whipping movements allow it to swim towards desired destination
Cytoplasm
Fluid filled space bound by membrane
Composed of intracellular fluid
Chromatin
Equal amounts of DNA and bead like proteins called histones
Nuclear envelope
Contain specialised pores to allow molecules to enter and leave nucleus
Nucleoli
Dark spherical bodies that synthesise the rna and proteins needed to form ribosomal subunits
Mitochondria
Contain own DNA
Able to replicate independently of the cell
Replicate through binary fission
Mitochondria - function
Energy production via synthesis of atp
Calcium storage and release
Synthesis of atp - ways
Krebs cycle
Electron transport chain
Ribosomes
Proteins combined with RNA
Two globular structures called subunits
Ribosome function
Reads coded message for protein in messenger rna and translate into chain of amino acids
Polypeptide
Conforms to the shape of protein
Membrane bound ribosomes
Synthesise proteins for incorporation into cellular membrane
Endoplasmic reticulum
Network of membrane that continuous with the nuclear envelope
Rough ER
Ribosomes bound to the ER
Smooth ER
Without ribosomes
Protein synthesis on Rough ER
Secreted from cells
Smooth ER function
Production of large amounts of cholesterol and steroids
Lipid metabolism
Detoxification of drugs, toxins and alcohol
Breakdown of stored glycogen
Golgi Appartus
Final stop of secreted proteins
Modifies proteins, like addition of carbs, then repackaged prior to secretion
Glycosylation
Adding sugar molecules to form glycoproteins
Golgi appartus structure
Stack of membrane bounded cisternqe
Different enzymes perform varies activies in the Golgi
Transition vesicles
Pinch off from surface carrying
Integral membrane proteins
Soluble proteins
Processing enzymes
Outbound pathway
Transition vesicles move toward the cis Golgi on microtubules
Coat protein is removed and vesicles fuse together
Sugars are added
Proteins move from cis to medial to trans Golgi
Vesicles pinch off and carry completed products
Inbound pathway
Using signals, the Golgi separates the products from processing enzymes and returns the enzymes back
Inbound vesicles are coated in coat protein
V snares
On vesicle surface
T snares
On surface of target membrane
V and t snares
Bind to each other die to complementary structures
Lysomes - function
Cell demolition
- digest particles taken into cell by endocytosis
Degrading and recycling worn out organelle
Break down stores glycogen, non useful tissue, bone
Secretory function - release content by exocytosis
Perixisomes - function
Breakdown fatty acids
Breakdown harmful chemicals
Synthesis of cholesterol
Oxidase function
Detoxify harmful substances
Neutralise and convert dangerous free radicals
Catalase
Convert harmful hydrogen peroxide made from oxidase to water
Extracellular matrix
Substance between cells
All cells in solid tissue are surrounded by ecm
Composed of proteins, complex chains of sugar
ECM function
Extracellular communication
Stable positioning of cells in tissue through adhesion
Repositioning of cells by cell migration
ECM properties
Tensile strength to tendons
Compressive strength to cartilage
Hydraulic protection for many cells
Elasticity to blood vessel walls
Main forms of ECM
Connective tissue
Basement membrane
Pericellular matrix
Cell Adhesion molecules
Located at cell surface and join cells to cells, cells to ECM and ECM to cell cytoskeleton
CAM function
Adhesion of cells to provide organised tissue structure
Transmission of extracellular cues and signals across membrane
Migration of cells through regulation of adhesions
