Cells and organelles Flashcards
lecture 1
What is the scales of eukaryotic cells?
10-100um, nanoliters
What are cell membranes made of?
Lipid bilayer made of phopholipid
What are structures in cells called? Are they in prokaryotes?
Organelles, which usually have a single bilayer. prokaryotes dont usually have ogranelles
What are the 6 most important organelles? What are their roles?
Nucleus-store DNA, make RNA, ribosomes
ER-SER lipid biosynthesis , RER - ribosomes on it-site of final foldig (S-S bonds), modification and sorting to golgi
Golgi- Cis medial and Trans- lieu of post translational modif and sorting to other organelles
Ribosome-not an organelle but place of protein synthesis in cytosol and near ER
Mitochondria-place of TCA and OxPhos-double layered
Lysosome-degradation of enzymes and some biocomponents
What molecules are found in a cell?
DNA, RNA, protein, nucleotides organelles, K+ (ions), signals, sugars, amino acids, lipids,
What can be found outside a cell?
ECM (fibrillar collagen, elastin, fibrilin, laminin, agreggan etc and ECF (Ca2+ (ions), soluble protsn sugars, vitamins, aa, hormones, nucleotides, lipids, lymph, plasma, saliva, etc)
What are the 3 components of the cytoskeleton?
Microtubules (inside cyto/highway), Intermediate filaments and microfilaments (actin)
What are the key differences between eukaryotes and prokaryotes?
No orgnanelles, circular DNA, usually smaller, single cell organisms, 70S ribosome
What are the key cancer mutations?
Increase of prolif, decrease of apoptosis, ability to avoid immunity, ability ot move tissue, loss of DNA repair
List the main functions of the blood
transport, heat distribution, immunity, haemostasis, homeostasis, connective tissue, maintain haemostasis
Explain the importance, basic structure and role of haemoglobin
Importance: carries 02 from lungs to tissue in erythrocytes
Basic struct: 2a 2b chains with an fe2+ group in the center-cooperative binding
Role-uptake of 02 cooperativly and CO2 as well
Explain the basic features of erythrocytes
Biconcave disc, with no organelles, very flexible and surface antigens provide blood group. Start as reticulocytes (with organelles) and mature to ose them. Live 120 days and are removed in reticulo-enothelial system
How is RBC production regulated
in low O2, and sufficient fe2+, kindey produce haematopoetin which tells BMSC to produce more RBC
What is aneamia?
a deficiency of RBC or haemoglobin
What are 4 key RBC parameters?
RBC conc, RBC count, heamatocrit (packed volume) and Mean cellular volume (MCV
What 3 types of aneamia are there? what are the causes?
Microcytic-small MCV, due to prolonged bleeding (periods, internal hemmoragy, cancer)
Normacytic-normal MCV-acute Bleeding
Macrocytic-lack of B12/folic acid to finish maturation-usually pregnancies or vegans
What are the main functions of Leukocytes?
Polymorphonuclear granulocytes-first oen to the site
Neutrophil-phagocytosis
Basophils-produce heparin
Eosinophils-allergies, cancer and parasites
Leukocytes -T and B cells
Monocytes-become macrophages and help repair tissue/eat up debris
Key feature and role of B lymphocyte
Mature in BM, part of hummoral response. Make Immunoglobulin in response to antigen-opsionise, aglutinate, precipitate or neutralise. Secondary response usually faster
Key features and role of T lymphocytes
Mature in thymus-when presented with AG-blast transfomation and become active. Can make chemotaxins (attract maco), lymphtoxin (kills cells) and interferons (kill viruses)
Key features and role of platelets
From megakaryocytes, small. Short life span, many organelles but no nucleus. HAve surface receptors for collagen or thrombin which releases granules-incresase thrombin cascade. Aspirin inhibites cyclogenase
What is plasma?
Fluid of blood (all inorganic and water)-proteins to maintain blood pressure and volume, albumin and glubulin carry insoluble molecules, fibrinogen can help clotting)
