Cell Structure & Function Lecture 5 Flashcards
Central dogma?
Organisms genotype is determined by their base sequence of their DNA, its phenotype is a product of the proteins from their DNA
Cytoplasms function?
Everything in the cell but not the nucleus, made up of the cytosol (fluid), the organelles within and the small molecules, proteins and nucleic acid that moves around
Plasma membranes function?
Physical barrier separating the inside and outside
of the cell
Membrane proteins mediate movement of
hydrophilic substances (semi permeable barrier).
Allows Cell- Cell identification
Facilitates intercellular communication.
What is a phospholipid?
hydrophobic tail, hydrophilic head
Integral membrane proteins?
1. Transmembrane proteins: integral membrane proteins that span the entire membrane, contact extracellular and cytoplasmic environments 2. Peripheral membrane proteins: associated with the membrane, but not actually embedded in it 3. Glycoproteins: integral proteins with a carbohydrate group attached, facing extracellular side, contributes to the glycocalyx or molecular signature of the extracellular side of the cell
Nucleus’s function?
House/protect DNA in eukaryotic cells
What is the nucleus enclosed by?
Nuclear envelope (double lipid bilayer), has nuclear pores
Nucleolus?
Houses rRNA production and assembly of ribosome subunits
Nucleotides contain?
Deoxyribose sugar, nitrogenous base and a phosphate group
Bonds within the nucleotide are?
Hydrogen bond, phosphodiester bond
Ribosome components and functions?
Large and small subunit, comprise rRNA in complex with proteins assembled (translation) in the nucleolus
Ribosomes are found where?
Cytoplasm, attached to the rough ER
What is the ER?
The ER is an extensive network of tubes and tubules, stretching out from the nuclear membrane
ER is found where?
Rough ER is connected to the nuclear membrane and the smooth ER branches off the rough ER
Rough ER functions?
Processing sorting and packaging of - Secreted proteins - Membrane proteins - Organelle proteins produced by ribosomes
What is the golgi complex?
Complex of a number of flattened membranous sacs cisternae, stacked on top of one another, curved into a cup shape
Smooth ER functions?
Production of lipids and carbohydrates in a cell housing unit for tissue specific proteins
• in the liver,
The smooth ER stores enzymes that are used to detoxify drugs or harmful substances
Golgi complex functions?
Modify, sort, package and transport proteins from the rough ER.
• Each sac (cisternae) contains enzymes of different
functions, proteins move from sac to sac, being modified
and sorted differently at each one
Lysosomes components?
Surface is a plasma membrane derived from that of the GC
Proteins in the plasma membrane pump H+ inside and allow enzymes to function in the lysosome
Inside are powerful digestive and hydrolytic enzymes.
Functions of the lysosome?
Digestion of - substances that enter a cell - cell components e.g. organelles (autophagy) - entire cells (autolysis); and - any extracellular digestion All building blocks are recycled
Mitochondria components?
Outer mitochondrial membrane;
Inner mitochondrial membrane, with folds called cristae;
Fluid filled interior cavity, called the mitochondrial matrix.
Mitochondrial functions?
Generation of ATP through cellular respiration
