Cell Structure and Respiration Flashcards
Five survival needs for the human body
Nutrients Oxygen Water Normal body temperature Appropriate atmospheric pressure
Eight functions necessary to maintain life
Maintenance of boundaries Movement Responsiveness Digestion Metabolism Excretion Reproduction Growth
The Cell Theory
A cell is a highly organised compartment bound by a plasma membrane that contains concentrated chemicals in an aqueous solution.
All organisms are made of cells which come from pre-existing cells.
The total function of all the cells in the body reflects the total function of the body.
Plasma membrane
Double phospholipid layer with a fluid mosaic model
Forms a cellular boundary
Selective permeability
Integral proteins add functions that allow cells to deal with the environment and each other
Phospholipids
Hydrophilic heads towards the edges
Hydrophobic tails towards the middle and each other
3 types of integral membrane proteins
Transmembrane
Peripheral
Glycoprotein
Transmembrane proteins
Span entire membrane
Contact both cytosol and extracellular fluid
Amphipathic
Peripheral membrane proteins
Attached to polar heads of phospholipids or other integral proteins
Not fully embedded in the membrane
Glycoproteins
Carbohydrate groups attached to protein body
Protein body protrudes into extracellular fluid
Carbohydrate portion form sugary coats called glycocalyx
Glycocalyx
Molecular signature so cells can recognise each other
6 functions of plasma membrane
Transport Enzymatic Signal transduction Recognition Intercellular joining Cytoskeleton and ECM attachment
Nucleus description
Nuclear envelope - lipid bilayer Lined by nuclear lamina which contains fibrous proteins Contains rough ER Nuclear pores for transport Contains nucleolus Houses DNA
Nucleolus
Site of rRNA production
Assembles ribosome subunits
DNA
Wrapped twice around group of histones to form nucleosomes known as chromatin
Condenses to chromatin fibres
Phosphate + deoxyribose sugar + phosphate base
Phosphodiester and hydrogen bonds
Endoplasmic Reticulum
Extensive network of tubes and tubules stretching out from nuclear membrane
Rough ER - processing, sorting and packaging of secreted proteins produced by ribosomes
Smooth ER - lipid and carbohydrate production, houses tissue specific proteins and can store detoxifying substances
Golgi Complex
Made up of cisternae - flattened membraneous sacs stacked on top of each other and curved into a C shape
Modifies, sorts, packages and transports proteins from rough ER
Proteins move between sacs being modified and sorted differently at each one
Entry at cis, packaged at trans
Lysosome
Vesicles formed by GA
Contain lysosomal enzymes which function using protons pumped into the cell
Used to digest parts of cell, ECM and cell itself
Autophagy
Cell compartment digestion by lysosomes
Autolysis
Entire cell digestion by lysosomes