Week 2 "Formation"

Question 1

What is the generic components of a generic membrane?

Answer 1

Phospholipids- (bilayer formation)
Cholesterol- (membrane integrity and fluidity)
Proteins- (integral or peripheral membrane proteins–important for cell function)
Carbohydrates- attached to lipids or proteins-contribute to cell-cell recognition etc.

Question 2

List the general role of biological membranes and describe each

Answer 2

Compartmentalisation- allows cell to carry out different metabolic reactions at the same time (generates different environments)
Electrochemical/membrane potential - semipermeable- ions may be controlled to serve function
Transport/protection- stops cell falling apart, monitors nutrient flow
Anchoring- interacts with proteins to anchor them in place- also interacts with cytoskeleton elements to maintain structure.

Question 3

List 4 types of membrane transport.

Answer 3

Simple diffusion- (across membrane
Facilitated diffusion- (requires a channel or carrier protein)
Primary active transport- (uses ATP)
Secondary active transport (ion coupled transport)-using chemical gradient of an ion to transport a solute against its concentration gradient

Question 4

Types of membrane protein transport

Answer 4

Uni-transport - one molecule

Co-transport - (Symport and antiport)

Question 5

Role of Smooth ER and Rough ER

Answer 5

Smooth- hormones and lipids

Rough- (presence of ribosome)- protein production

Question 6

Role of lysosomes and peroxisomes

Answer 6

Lysosomes- digestive organelle

Peroxisomes- detoxification

Question 7

What is mitosis

Answer 7

Cyclical sequence of events resulting in production of 2 identical daughter cells
(somatic cells)

Question 8

What is cell differentiation

Answer 8

The process in which a cell becomes more specialised.

Question 9

What is a stem cell

Answer 9

They are undifferentiated cells which are capable of self renewing (making more of themselves) as well as differentiating into more specialised cell types.

Question 10

Differentiate:
Totipotent
Pluripotent
Multipotent

Answer 10

T- most versatile- can differentiate to any cell
P- can give rise to all differentiated body cells but not entire organism
M- can give rise to more than one cell type (much more limited)

Question 11

What is apoptosis and its role in embryo development

Answer 11

It is a programmed form of cell death.

In development ensures proper formation of fingers. etc

Question 12

What is the central dogma of molecular biology?

Answer 12

DNA–>RNA–>Protein

Question 13

What is DNA replication

Answer 13

Process in which DNA is replicated (usually before cell division)
Parental strand used as template for daughter strand.

Question 14

What is transcription

Answer 14

DNA–>mRNA (RNA pol in nucleus)

Question 15

What is translation

Answer 15

mRNA–> Protein (at ribosome in cytoplasm)

Question 16

What are the universal features of the genetic code

Answer 16

1. Three nucleotides per base (amino acid)
2. non overlapping- (groups of 3 read in order)
3. degenerate- more than one triplet can code for a particular amino acid.

Question 17

What is some features of a chromosome structure.

Answer 17

1. 2 chromatids (sister)
2. telomeres -stable ends of a chromatid
3. centromeres
4. diploid organisms have 2 sets of chromosomes (2 allele options)

Question 18

In translation what order do the tRNA enter the ribosome

Answer 18

1st enters the P site
2nd enters the A site
both shift over- P tRNA moves to E and exits
new tRNA enters in A site.
order of A-P-E

Question 19

What portion of the nuclear genome is gene coding

Answer 19

25% is genes/gene related
of this portion
10% coding DNA

Question 20

Structure of nuclear genome

Structure of mitochondrial genome

Answer 20

Nuclear genome - (large)
1.DNA wrapped around histones
2. condensed into chromosome structure
Mitochondrial genome- (small)
1. Small number of genes in plasmid configuration

Question 21

What is a gamete

Answer 21

sex cells (haploid)

Question 22

what is an Embryo

Answer 22

as the zygote divides into more cells it is then termed an embryo (in humans considered embryo up until the 9th week post fertilisation or 11 week gestational age

Question 23

what is a zygote

Answer 23

fusion of male and female sex cell (diploid) (fertilised ovum)

Question 24

what is a foetus

Answer 24

larger multicellular organism stage after embryo (yet to be born)

Question 25

What is the ectoderm

give example of structures+cell types

Answer 25

the outermost layer of cells or tissue of an embryo in early development, or the parts derived from this. eg skin and nervous system.

Question 26

What is the mesoderm

give example of structures+cell types

Answer 26

the middle layer of cells or tissues of an embryo, or the parts derived from this (e.g. cartilage, muscles, and bone).

Question 27

What is the endoderm

give example of structures+cell types

Answer 27

The innermost layer of cells or tissue of an embryo in early development, or the parts derived from this eg gastrointestinal linings and pulmonary sytem

Question 28

What are the three germ layers

Answer 28

Ectoderm
Mesoderm
Endoderm

Question 29

Developmental events in the first trimester

Answer 29

Week 0- Last menstrual period
Week 2- Fertilization (sperm and ovum fusion)
Week 2 till Week 10 - embryogenesis and organogenesis (organs formed)

Question 30

Developmental events in the second trimester

Answer 30

Week 13-16- sensory organ development
Week 16-20- fetus may begin to move (may be as late as week 25)
Week 24- 50% survival of foetus outside the womb
Week 24 - lungs develop further

Question 31

Developmental events in the third trimester

Answer 31

Third trimester
Week 37- organs capable of functioning outside womb
Week 40- full term

Question 32

Common methods to determine whether pregnancy is progressing normally.

Answer 32

Imaging- ultrasound to determine any physical abnormalities
foetal echocardiography- using a doppler ultrasound to view heart in more detail.
DNA sampling- to check for genetic disorders
Physical exam- assess mothers size, auscultate, palpate