Cells and organelles

Question 1

What is the scales of eukaryotic cells?

Answer 1

10-100um, nanoliters

Question 2

What are cell membranes made of?

Answer 2

Lipid bilayer made of phopholipid

Question 3

What are structures in cells called? Are they in prokaryotes?

Answer 3

Organelles, which usually have a single bilayer. prokaryotes dont usually have ogranelles

Question 4

What are the 6 most important organelles? What are their roles?

Answer 4

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

Question 5

What molecules are found in a cell?

Answer 5

DNA, RNA, protein, nucleotides organelles, K+ (ions), signals, sugars, amino acids, lipids,

Question 6

What can be found outside a cell?

Answer 6

ECM (fibrillar collagen, elastin, fibrilin, laminin, agreggan etc and ECF (Ca2+ (ions), soluble protsn sugars, vitamins, aa, hormones, nucleotides, lipids, lymph, plasma, saliva, etc)

Question 7

What are the 3 components of the cytoskeleton?

Answer 7

Microtubules (inside cyto/highway), Intermediate filaments and microfilaments (actin)

Question 8

What are the key differences between eukaryotes and prokaryotes?

Answer 8

No orgnanelles, circular DNA, usually smaller, single cell organisms, 70S ribosome

Question 9

What are the key cancer mutations?

Answer 9

Increase of prolif, decrease of apoptosis, ability to avoid immunity, ability ot move tissue, loss of DNA repair

Question 10

List the main functions of the blood

Answer 10

transport, heat distribution, immunity, haemostasis, homeostasis, connective tissue, maintain haemostasis

Question 11

Explain the importance, basic structure and role of haemoglobin

Answer 11

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

Question 12

Explain the basic features of erythrocytes

Answer 12

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

Question 13

How is RBC production regulated

Answer 13

in low O2, and sufficient fe2+, kindey produce haematopoetin which tells BMSC to produce more RBC

Question 14

What is aneamia?

Answer 14

a deficiency of RBC or haemoglobin

Question 15

What are 4 key RBC parameters?

Answer 15

RBC conc, RBC count, heamatocrit (packed volume) and Mean cellular volume (MCV

Question 16

What 3 types of aneamia are there? what are the causes?

Answer 16

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

Question 17

What are the main functions of Leukocytes?

Answer 17

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

Question 18

Key feature and role of B lymphocyte

Answer 18

Mature in BM, part of hummoral response. Make Immunoglobulin in response to antigen-opsionise, aglutinate, precipitate or neutralise. Secondary response usually faster

Question 19

Key features and role of T lymphocytes

Answer 19

Mature in thymus-when presented with AG-blast transfomation and become active. Can make chemotaxins (attract maco), lymphtoxin (kills cells) and interferons (kill viruses)

Question 20

Key features and role of platelets

Answer 20

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

Question 21

What is plasma?

Answer 21

Fluid of blood (all inorganic and water)-proteins to maintain blood pressure and volume, albumin and glubulin carry insoluble molecules, fibrinogen can help clotting)