Chapter 1- Themes In The Study Of Life

Question 0

Reductionism

Answer 0

The approach of reducing complex systems to simpler components that are more manageable to study

Question 1

What is an emergent property?

Answer 1

The arrangement and interaction of parts as complexity increases

Question 2

What is a system?

Answer 2

A combination of components that function together

Question 3

What are the characteristics of life?

Answer 3

• highly organized structure
• energy processing
• homeostasis
• responds to environment
• reproduction
• change over time

Question 4

Eukaryotic cell

Answer 4

Subdivided by internal membranes into various membrane enclosed organelle

Question 5

The biggest organelle that contains the cells DNA

Answer 5

Nucleus

Question 6

Cytoplasm

Answer 6

The entire region between the nucleus and the outer membrane of the cell

Question 7

Chloroplasts

Answer 7

An organelle found in eukaryotic cells that carries out photosynthesis

Question 8

Prokaryotic Cells

Answer 8

DNA is not separated from the cells by a nucleus

Question 9

DNA

Answer 9

Deoxyribonucleic Acid

Question 10

Genes

Answer 10

The units of inheritance that transmit information from parent to offspring

Question 11

Selective permeability

Answer 11

Membranes allow some substances to cross more easily than others

Question 12

Amphipathic

Answer 12

A molecule that has both a hydrophilic and hydrophobic region. A phospholipid is amphipathic

Question 13

Fluid mosaic model

Answer 13

Draw the fluid mosaic model and check in the book
The membrane is a fluid structure with a “mosaic” of Various proteins embedded in or attached to a double layer (bilayer) of phospholipids.

Question 14

Freeze-fracture

Answer 14

Splits a membrane along the middle of the bilayer using liquid nitrogen.

Question 15

Fluidity of membranes

Answer 15

A membrane is held together by hydrophobic interactions which are much weaker than covalent bonds. Most of the lipids and some of the proteins can shift about laterally. They do so several times per second. It is much more difficult to shift vertically and is only one once a month because the hydrophilic part of the molecule must cross the hydrophobic region.

Question 16

Integral proteins

Answer 16

Penetrate the hydrophobic interior of the lipid bilayer of a cell.

Question 17

Peripheral proteins

Answer 17

Appendages loosely bound to the surface of the membrane of a cell

Question 18

Membrane carbohydrates

Answer 18

Short, branched chains of fewer than 15 sugar units

Question 19

Glycolipids

Answer 19

A membrane carbohydrate covalently bonded to lipids

Question 20

Glycoproteins

Answer 20

A membrane carbohydrate covalently bonded to a protein

Question 21

Synthesis and sidedness of membranes

Answer 21

The asymmetrical arrangement of proteins, lipids and their associated carbohydrates in the plasma membrane is being build by the endoplasmic reticulum and the Golgi apparatus. See fig 7.12

Question 22

Supramolecular structure

Answer 22

Many molecules ordered into a higher level of organization

Question 23

Permeability of the lipid bilayer

Answer 23

No polar molecules are hydrophobic and can dissolve in the lipid bilayer as cross it easily.
Polar molecules do not cross vey rapidly.

Question 24

Transport proteins

Answer 24

Function by having a hydrophilic channel that certain molecules or atomic ions use as a tunnel through the membrane figure 7.10a