Cell structure and function Flashcards
What is the classified as cytoplasm within the cell?
Everything within the plasma membrane excluding the nucleus
State the organs within the endomembrane system
Nucleus
Endoplasmic Reticulum (rough and smooth)
Golgi apparatus
Lysosomes
Which organs are not within the endomembrane system
Mitochondria/ RIbosomes
Function of the Plasma Membrane
Selectively permeable barrier controlling the passage of substances in and out of the cell
Describe the structures of the Plasma membrane
Hydrophillic polar heads (phosphate)
Hydrophobic lipid tails (fatty acids)
Arranged in a double layer
Has plasma proteins
Describe the function of the Plasma Membrane Proteins
Mediate the movement of hydrophobic regions
allow cell to cell identification and intercellular communication
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Describe some of the 6 jobs of the plasma membrane proteins
Transport, enzymatic activity, signal transduction
Cell to cell regonition, Intercellular joining, attachment to the cytoskeleton and ECM
What does the nucleus do
Stores DNA. makes RNA and ribosomes
Pores regulate movement of substances (proteins and mRNA in and out)
Gene
a DNA segment that contributes to phenotype/ function
Chromosome
comprises many genes
Describe the structure of DNA
DNA is wrapped around 8 histones to form nucleosomes which are collectively known as chromatin
What does coiling determine in a nucleus
accessibility
Ribosomes structure
Two subunites : small and large ribosomal RNA (Rrna) in a complex with many proteins
WHat does the nucleous do?
rRna production, assembly of small and large subunits of ribosomes
Function and location of Ribosomes within the cell
Protein production (translation) found attached to the RER and free in the cytoplasm
What is the ER structure
Extensive network of tubes and tubules stretching from the nuclear membrane
RER function
Production of: Secrete proteins Membrane proteins Organelle Proteins Transport vesicle destined for the Golgi
Smooth ER
Lacks ribosomes- does not make proteins
Housing unit for proteins and enzymes
Very cell/tissue specific
Golgi aparatus function
modify, sort, package and transport proteins received from the rough ER using enzymes in each cisternae
What does the Golgi form
secretory vesicles
Membrane vesicles
Transport vesicles
FUnction of Lysosomes
Powerful digestive enzymes
Digestion of substances that enter the cell
Cell components eg oragnelles- autophagy
Entire cells- autolysis
Structures within the Mitochondria
Inner mitchondral membrane
Fluid within the interior cavity- matrix
Outer mitochondrial membrane
Function of the Mitochondria
Generation of ATP through cellular respiration
Function of cytoskeletons
Structural support of the cell
Types of cytoskeleton
Smallest to largest. Microfilaments/ Intermediate filaments
Microtubules
Describe Microfilaments
comprised of actin and are dynamic
Describe Intermediate filaments
Keratin found in filament. Most permanent
Describe Microtubles
Comprised of tubulin and are dynamic
Support the movement of cilia and flagella
