Cells and membranes Flashcards
What is the difference between cell death through necrosis and apoptosis?
Apoptosis is physiological, individual cells die over hours and cause no damage/inflammation to adjacent cells;
Necrosis is pathological, groups of cells die over days, their membranes burst and cell contents cause damage and inflammation to adjacent cells
What is the difference between pluripotent and multipotent stem cells?
Pluripotent can turn into all cell types in the body, multipotent can turn into all cell types in certain tissues
What characteristics separate prokaryote cells from eukaryote cells?
Prokaryotes have no nuclear membrane, no mitochondria and do not have organelles surrounded by membranes
Name five different classes of cell-cell junctions
Gap junctions tight junctions desmosomes (intermediate keratin filaments) adherens junctions (actin filaments) hemidesmosomes
What different types of structures make up the cytoskeleton?
Microfilaments (actin)
intermediate filaments (fibrous keratin)
microtubules
What are the main characteristics of mitochondria?
their own DNA, ribosomes and proteins
self replicate
an inner membrane arranged in cristae
produce energy from breakdown of molecules
What are the main characteristics of the nucleus?
Contain DNA (heterochromatin or euchromatin), membrane bound with pores
What are the structural and functional differences of the smooth and rough endoplasmic reticulum?
RER - has ribosomes on its surface, it’s mainly involved in protein synthesis (RNA translation into amino acid sequences)
ER - mostly involved in breakdown of molecules (eg drugs) and synthesis of some molecules (eg lipids)
What is the role of lysosomes?
They contain digestive enzymes for breakdown of cell’s or foreign molecules
What are the 10 main elements of life?
H - hydrogen, O - oxygen, N - nitrogen, C - carbon, Na - sodium, S - sulphur, P - phosphorus, Cl - chloride, K - potassium, Ca - calcium
List the five chemical reaction of life
Reduction/oxidation Making/breaking C-C bonds Group transfers Internal rearrangements Condensation/hydrolysis
What do oxidation and reduction mean respectively?
Oxidation Is Loss of electron (OIL)
Reduction Is Gain of electron (RIG)
define configuration and conformation of a molecule
configuration - fixed arrangement of molecules, can only be altered by breaking and reforming bonds
conformation - specific arrangement of molecules, which can change depending on their interaction without making/breaking bonds
what ties together nucleic acid monomers?
covalent phosphodiester bonds
what are the purines in nucleic acid and their characteristics?
Guanine
Alanine
double ring bases
what are the pirimidines in nucleic acid and their characteristics?
thymine
uracil
cytosine
single ring bases
what is the chiral centre of a molecule?
the center of an asymmetric molecule
what are features of glucose that causes it to have reducing and non-reducing ends?
when polymers are made glucose sits in ring shape (non reducing)
the end group of the molecule is linear (ALDEHYDE) and reducing
what is the concept of energy coupling in cells?
coupling an anabolic with a catabolic reaction, to use energy from spontaneous reaction to fuel an energetically unfavourable reaction