Cell Structure & Function Lecture 5

Question 1

Central dogma?

Answer 1

Organisms genotype is determined by their base sequence of their DNA, its phenotype is a product of the proteins from their DNA

Question 2

Cytoplasms function?

Answer 2

Everything in the cell but not the nucleus, made up of the cytosol (fluid), the organelles within and the small molecules, proteins and nucleic acid that moves around

Question 3

Plasma membranes function?

Answer 3

Physical barrier separating the inside and outside
of the cell
Membrane proteins mediate movement of
hydrophilic substances (semi permeable barrier).
Allows Cell- Cell identification
Facilitates intercellular communication.

Question 4

What is a phospholipid?

Answer 4

hydrophobic tail, hydrophilic head

Question 5

Integral membrane proteins?

Answer 5

1. Transmembrane proteins: integral
membrane proteins that span the entire
membrane, contact extracellular and
cytoplasmic environments
2. Peripheral membrane proteins: associated
with the membrane, but not actually
embedded in it
3. Glycoproteins: integral proteins with a
carbohydrate group attached, facing
extracellular side, contributes to the
glycocalyx or molecular signature of the
extracellular side of the cell

Question 6

Nucleus’s function?

Answer 6

House/protect DNA in eukaryotic cells

Question 7

What is the nucleus enclosed by?

Answer 7

Nuclear envelope (double lipid bilayer), has nuclear pores

Question 8

Nucleolus?

Answer 8

Houses rRNA production and assembly of ribosome subunits

Question 9

Nucleotides contain?

Answer 9

Deoxyribose sugar, nitrogenous base and a phosphate group

Question 10

Bonds within the nucleotide are?

Answer 10

Hydrogen bond, phosphodiester bond

Question 11

Ribosome components and functions?

Answer 11

Large and small subunit, comprise rRNA in complex with proteins assembled (translation) in the nucleolus

Question 12

Ribosomes are found where?

Answer 12

Cytoplasm, attached to the rough ER

Question 13

What is the ER?

Answer 13

The ER is an extensive network of tubes and tubules, stretching out from the nuclear membrane

Question 14

ER is found where?

Answer 14

Rough ER is connected to the nuclear membrane and the smooth ER branches off the rough ER

Question 15

Rough ER functions?

Answer 15

Processing sorting and packaging of 
- Secreted proteins
- Membrane proteins
- Organelle proteins
produced by ribosomes

Question 16

What is the golgi complex?

Answer 16

Complex of a number of flattened membranous sacs cisternae, stacked on top of one another, curved into a cup shape

Question 17

Smooth ER functions?

Answer 17

Production of lipids and carbohydrates in a cell housing unit for tissue specific proteins
• in the liver,
The smooth ER stores enzymes that are used to detoxify drugs or harmful substances

Question 18

Golgi complex functions?

Answer 18

Modify, sort, package and transport proteins from the rough ER.
• Each sac (cisternae) contains enzymes of different
functions, proteins move from sac to sac, being modified
and sorted differently at each one

Question 19

Lysosomes components?

Answer 19

Surface is a plasma membrane derived from that of the GC
Proteins in the plasma membrane pump H+ inside and allow enzymes to function in the lysosome
Inside are powerful digestive and hydrolytic enzymes.

Question 20

Functions of the lysosome?

Answer 20

Digestion of 
- substances that enter a cell
- cell components e.g. organelles (autophagy)
- entire cells (autolysis); and
- any extracellular digestion
All building blocks are recycled

Question 21

Mitochondria components?

Answer 21

Outer mitochondrial membrane;
Inner mitochondrial membrane, with folds called cristae;
Fluid filled interior cavity, called the mitochondrial matrix.

Question 22

Mitochondrial functions?

Answer 22

Generation of ATP through cellular respiration