Lecture 1 - Introduction to the living cell

Question 1

Cell Theory (3)

Answer 1

1. Both animal and plant tissue are composed of cells
2. Cells are the basic unit of all life
3. Cells only develop from existing cells

Question 2

Three major domains of cells (3)

Answer 2

Bacteria (Eubacteria) 
Archaea (Archaebacteria) 
Eukaryotes

Question 3

Universal features of all cells on Earth (11)

Answer 3

Phospholipid bilayer.
Exchanging molecules with their environment e.g. sugars, amino acids, ions and proteins etc.
Cells communicate e.g.cascade events.
Heredity info stored in DNA e.g. Nucleotides –> Strands -> DNA double helix
DNA fragment corresponding to a single protein = a gene
Occurs via DNA synthesis (replication), then RNA synthesis (transcription) and protein synthesis (translation).Translate RNA into protein in the same way.
Sunlight is the ultimate source of most biological energy egPhotosynthesis, food webs/trophic levels etc.
Role of ATP as the main energy currency (in metabolism).
Homeostasis.
Evolution.
“Life is a pattern of flux”.

Question 4

Replacing body cells (3)

Answer 4

Molecules in our body are almost continuously being replaced, i.e. they have a turnover rate (e.g. water). Some tissues have a higher turnover rate than others, for example RBC 120 days, Skeleton 10 years

Question 5

Gene

Answer 5

DNA fragments corresponding to one protein.