AS - Water and its importance

Question 1

Water structure

Answer 1

H-O-H
joined by hydrogen bond
Hydrogen - Slight positive charge
Oxygen - Slight negative charge

Question 2

Water properties

Answer 2

Liquid at normal temperature 
Cohesive and adhesive
high specific heat capacity 
unusual density
high latent heat capacity
chemical reactant

Question 3

Inorganic

Answer 3

Simple don;t contain Hydrogen and oxygen

Question 4

Organic

Answer 4

Contain hydrogen and oxgen

Question 5

Osmosis

Answer 5

Net movement
HIGH —> LOW water potential
Passive
(through partially permeable membrane)

Question 6

Water Potential

Answer 6

(KF) Move and collide with cell membrane –> creates pressure measured in KPa
Pure water = 0kpa
more solute = lower water potential
Osmosis evens water potential out until it reaches dynamic equilibrium where it’s even therefore there is no further net movemt

Question 7

Anabolic

Answer 7

Build large molecules from smaller ones

Question 8

Catabolic

Answer 8

Breakdown large molecules into smaller ones

Question 9

Water Is a Solvent

Answer 9

form shell around charged ions, prevents from clumping so dissolves.
Importance: transports substances, removes metabolic waste, allowing chemical reactions to take place inside cells

Question 10

Water has a high specific heat capacity

Answer 10

Ideal habitat for aquatic organisms. Prevents internal body temperature changing quickly

Question 11

Water has a high latent heat of vaportisation

Answer 11

Allows our body to lose heat through sweating, requires large amount of heat to break the hydrogen bond

Question 12

Water is cohesive and adhesive

Answer 12

Used as lubricant in form of pleural fluid (to minimise friction between lungs and thoracic rib cage)

Question 13

Three diffeernces between tissue fluid and blood

Answer 13

TF: NO red blood cells, no haemoglobin
No platelets/ low pressure, Not in vessels
BLOOD: red blood cells, full range of white blood cells, high pressure, contained in vesicles

Question 14

Blood

Answer 14

no nucleus allows more hemoglobin - carries oxygen. Allows it flexible squeeze through capillaries,

Question 15

Glucose

Answer 15

Carried in blood, stored in tissues, soluble in water, energy source, bonds can be broken to release energy to form ATP, monomer: can participate in condensation reactions to form disaccharides

Question 16

Pressure

Answer 16

High in aorta as comes from heart, lost during formation of tissue fluid

Question 17

Blood (in artery)

Answer 17

Role: transport around body
Cells: erythrocytes, leucoctyes, platelets
Proteins: Hormones and plasma proteins
Glucose: present 80-120mgcm
Amino Acids: present
Oxygen: Present in arteries, less in veins
Carbon Dioxide: Little in arteries, more in veins
Flow Speed: fast

Question 18

Plasma

Answer 18

Role: Transport around body
Cells: No cells
Proteins: Hormones and plasma proteins
Glucose: present 80 -120mgcm
Amino Acids: present
Oxygen: present
Carbon Dioxide: little
Flow Speed: fast

Question 19

Tissue Fluid

Answer 19

Role: bathes cells, cells exchange substances directly with tissue fluid
Cells: some phagoctytic leucocytes
Proteins: no plasma proteins some hormones and proteins secreted by body
Glucose: less than blood in arteries (used in respiration)
Amino Acids: Less than blood in arteries (used by cells in protein synthesis)
Oxygen: less than blood in arteries (used by cells in respiration)
Carbon dioxide: more than blood in arteries (produced by cells in respiration)
Flow speed: none

Question 20

Lymph

Answer 20

Role: returns excess tissue fluid to blood
Cells: lymphocytes (produced in lymph nodes)
Proteins: Some large proteins secreted by cells
Glucose: Less than tissue fluid
Amino Acids: Less than tissue fluid
Oxygen: Less than tissue fluid
Carbon Dioxide: More than blood in arteries
Flow speed: very slow

Question 21

What is serum?

Answer 21

Serum is blood plasma from which blood clotting factors have been removed using diagnosticc tests i.e. blood typing

Question 22

Plant Biofluid: Cytosol

Answer 22

The liquid component of the cytoplasm in the intact cell (excluding any part contained within organelles)

Question 23

Plant Biofluid: Cell Sap

Answer 23

The liquid contained within the vacuole. Contains may dissolved substances and contributes to mechanical stability of the plant

Question 24

Plant Biofluid: Phloem Sap

Answer 24

Contains dissolved sucrose being transported in the phloem from the leaves where it is made to other parts of the plant

Question 25

Plant Biofluid: Xylem

Answer 25

The contents of the xylem tissue in plants carry water from the roots to other parts of the plant. Like the phloem, it contains ions and some organic molecules such as plant hormones but no sucrose

Question 26

CARBOHYDRATES, polymer, monomer, elements

Answer 26

Polymer: polysaccharides Monomer: monosaccharides Elements: carbon, hydrogen, oxygen

Question 27

PROTEINS, polymer, monomer, elements

Answer 27

Polymer: Polypeptides Monomer: Amino Acids Elements: hydrogen, oxygen, nitrogen, carbon

Question 28

NUCLEIC ACIDS, polymer, monomer, elements

Answer 28

Polymer: polynucleotides Monomer: nucleotides Elements: carbon, oxygen, nitrogen, hydrogen, phosphorus

Question 29

Condensation vs Hydrolysis

Answer 29

Condensation: lose a water molecule Hydrolysis: Add a water molecule

Question 30

Difference between alpha and beta glucose

Answer 30

Same molecular formula, but they have a different spatial arrangement of atoms. The hydrogen group is below the ring in Alpha glucose and above the ring in Beta glucose. ABBA

Question 31

Monosaccharides

Answer 31

Ribose: present in ATP and RNA Deoxyribose: present in DNA Fructose: fruit sugar, combines with glucose to form sucrose Galactose: combines with glucose

Question 32

Lactose

Answer 32

alpha glucose + galactose. Contains a beta-glycosidic bond present in milk energy source for nursing infants split into alpha glucose and galactose by the enzyme lactase, secreted from the intestinal villi, monosaccharides can then be absorbed.

Question 33

Sucrose

Answer 33

alpha glucose + fructose, form of sugar in which carbohydrates are transported in the phloem of plants can also be used as a storage carbohydrate.

Question 34

3 Advantages of storing glucose as a strach/glycogen

Answer 34

compact, inter, insoluble in water

Question 35

Starch is a mixture of

Answer 35

Amylose and amylopectin

Question 36

Amylose

Answer 36

spiral - glycosidic linkages, straight unbranched chain coiled into spiral

Question 37

Amylopectin

Answer 37

Branched - Compact branched structure

Question 38

Test for reducing sugars

Answer 38

Add benedict's reagent, heat to 80C in water and bath for 5 minutres, present = changes blue to red

Question 39

Test for Non-Reducing sugars

Answer 39

Add benedict's reagent and heat to 80C in water bath for 5 minutes. present = changes Blue to orange

Question 40

Test for proteins

Answer 40

Add buiret reagent, no heat required. Present = changes blue to purple

Question 41

Test for Starch

Answer 41

Add iodine solution, no heat required. Present = changes orange to black

Question 42

Biosensor

Answer 42

An analytical devise used to detect the presence of a chemical by using a biological component e.g. an enzyme or antibody. If the chemical binds, a colour or electrical charge is produced.

Question 43

Hypertonic

Answer 43

Higher water potential inside cell ---> animal cell = crenated (shrivelled) ---> plant cell = plasmolysed when plasma membrane has pulled away from cell wall

Question 44

Isotonic

Answer 44

same water potential inside and outside of cell, no net movment ---> Animal cell + plant cell = normal

Question 45

Hypotonic

Answer 45

higher water potential outside of cell ---> animal cell = lyse (burst), plant cell = turgid (swollen)