Cell biology primer

Question 1

levels of organisation:

Answer 1

• organelle - inside the cells, lots of them with different jobs
• cell
• tissue - cells are organised into tissues that do a certain job
• organ
• organ system - organs play specific roles within systems in the body
• organism - has different systems but they dont work alone

Question 2

jobs of the cells

Answer 2

• detecting - sensory neurons, pancreatic beta cells
• signalling - neurons, endocrine cells
• digesting, absorbing or transporting - epithelial cells, red blood cells, exocrine cells
• fighting infection - leukocytes
• moving - cardiac muscle, smooth muscle or skeletal muscle cells

Question 3

processes of the cells

Answer 3

• make things e.g., proteins, lipids
• break things down e.g., glucose, proteins
• change membrane voltage especially neurons
• secrete/transport things e.g., neurotransmitters
• detect things e.g., light, sound

Question 4

cell membrane

Answer 4

• a thin coat of phospholipids that surrounds a cell and controls what enters and leaves the cell.
• cells can control how things get in and out by altering the number of these different proteins in the membrane.

Question 5

cytoplasm

Answer 5

• the material inside the cell membrane, including the watery cytosol and other cell structures except the nucleus if one is present.
• cytosol contents:
• water
• ions
• small molecules
• amino acids
• soluble proteins

Question 6

cytoskeleton

Answer 6

• consists of filaments and tubules that crisscross the cytoplasm and help maintain the cells shape
• forming the structure of the cell

Question 7

nucleus

Answer 7

• an organelle that contains most of the cells DNA and acts as the control centre of the cell
• where DNA is stored

Question 8

DNA

Answer 8

• a nucleic acid found in cells
• it contains the genetic instructions that cells need to make proteins

Question 9

ribosomes

Answer 9

• structures found in all cells that are site of protein synthesis

Question 10

endoplasmic reticulum

Answer 10

• an organelle that helps make proteins and lipids and transports proteins in the cell
• takes the proteins from ribosomes and moves them onto the next bit

Question 11

Golgi apparatus

Answer 11

• an organelle that modifies, sorts, and packages proteins for secretion out of the cell, or for use within the cell

Question 12

lysosomes

Answer 12

• organelles that use enzymes to break down molecules so their components can be recycled

Question 13

mitochondria

Answer 13

• organelles that use energy stored in glucose to make ATP, which cells can use for energy

Question 14

proteins

Answer 14

• antibodies
• structural proteins e.g.,collagen
• contractile proteins e.g., myosin
• transport proteins e.g., haemoglobin
• storage proteins e.g., ferritin
• enzymes e.g., ATP synthetase
• hormonal proteins e.g., insulin

Question 15

alternative splicing

Answer 15

• RNA binding proteins chop out introns and stick exons together
• different RNA binding proteins in a given cell stick different exons together
• get lots of different proteins is made from a single gene

Question 16

protein structures

Answer 16

• primary structure - amino acid
• secondary structure - a-helixes
• tertiary structure - polypeptide chains
• quaternary structure - complex of protein molecule

Question 17

different cells express different proteins

Answer 17

• red blood cells - haemoglobin
• pancreatic beta cells - insulin
• neurons - ion channels
• muscle cells - myosin and actin

Question 18

ATP synthesis

Answer 18

• you can use/make approximately half of your whole body weight of ATP every day

Question 19

what does ATP do?

Answer 19

• drive reactions
• muscle contraction and dilation
• move molecules against gradients
• transport proteins or organelles around the cell
• move microtubules to allow cells to crawl or processes to move
• produce heat to maintain body temperature