This document provides an overview of biology from the levels of cells to organ systems. It discusses that biology is the study of life and living organisms. Cells are the basic unit of structure and function, and they combine to form tissues, organs and organ systems like the respiratory, digestive and circulatory systems. The key cellular structures and their functions are described. The processes of cellular respiration and photosynthesis are explained in terms of breaking down glucose and releasing energy. The roles of enzymes, ATP and metabolic pathways like glycolysis, Krebs cycle and electron transport chain are outlined. Cell transport mechanisms like diffusion, osmosis and active transport are also summarized.

1. SENSITIVITY NUTRITION RESPIRATION EXCRETION MOVEMENT
GROWTH
REPRODUCTION
Biology
PROCARYOTE EUCARYOTE
DIVISION OF WORK
MULTICELLULAR plants or animals
contain millions of
SPECIALIZATION
ORGANELLES  CELLS  TISSUES ORGANS  SYSTEM  ORGANISM
RESPIRATORY
SYSTEM
DIGESTIVE
SYSTEM
CIRCULATORY
SYSTEM
NERVOUS
SYSTEM
ENDOCRINE
SYSTEM
EXCRETORY
SYSTEM
REPRODUCTIVE
SYSTEM
MADE UP BY CELLS
Ability to
detect
STIMULI and
react to
them
*gaseous
exchange
*BREATHING
Chemical
reaction in
the cell that
releases E
from food
(break down
+ O2)
Obtaining
nutrients from
environment
that provide
them with E
and materials
Removal of the
waste products
generated in
the chemical
reactions
(METABOLISM)
Movement in
whole body or
parts to
change
position or
place
PERMANENT
increase in
SIZE and
MASS by
increase the
number or
size of a cell
Making new
organisms
LIKE ITSELF
Animal cell
1 divides/ 1 specializesCell
*grows
*change shape (adapt to
fuction)
*lose ability to %
Plant cell
Generates cell wall / specialized-> vacuole
is the science that studies life and living organisms

3. ENZYME
1) CATALYST => speed up chemical reactions Catabolism (respiration)/Anabolism
(building up of proteins)
But NO CHANGE/can be re used
2) PRoTEINS => aminoacids=> CHON
3) SPECIFIC : act on ONE substance (break down)/ a pair of substances (build up)=>
SUBSTRATE Hydrogen perioxide (H2O2)+ catalase = H2O+O
4) Higher t °/ faster they act : Optimum t °40° C
+ than 40° C => cross linkages break down/loses shape
and properties DENATURATION
5) PH is a measure of ACIDITY (-7) or ALKALINITY (+7)and is a
mathematical method for expressing the concentration of H+
ions in solution.
Most enzymes work best at a ph of 7/ They are affected by extremes of ph --
Exceptions: pepsin ph2 amylase ph 7 or +7
6) Present in a) membrane system b) mitochondria c) special vacuoles d) cytoplasm
Typical organelles Organelles present in
both
Typical organelles
*Lysosomes (digest
things)
*Cell membrane (no
escaping/maintains
struct/ controls subst
that enter or leave)
*Cell wall (shape/not
bursting)=> cellulose/
PERMEABLE
*centrioles (cellular %) *Nucleus (control center
DNA)
*Plastids (STARCH)
Chloroplasts =>
CHLOROPHYLL(photosynthesis)
*several vacuoles NOT
permanent
*Cytoplasm
*Nucleolus (make
ribosomes)
*Central vacuole(keep plant
upright) SAP
*Ribosomes (generate
proteins)
*Mitochondria (generate
E)
*Smooth Endoplasmic
Reticulum (toxic/lipids)
*Rough Endoplasmic
Reticulum (transport
proteins)
*Golgi Apparatus
(packaging/distribution)

4. Water
soluble
NOT soluble in WATER  food
storage
CHO
Physiology of a whole organism is the physiology of its component cells !!!!
How long could the people have remained alive in the water?
On the night of the Titanic sinking, the temperature of the salt water was likely
around 28° F(-2 °C). The human body loses heat to the water about 30 times
faster than it does to the air. When the core body temperature falls to
approximately (31°C), a decrease in consciousness occurs. If the core
temperature cools to below 86° F(30°C) then heart failure becomes a major
concern, as it is the most common cause of hypothermia-related deaths. The
people in the -2 °C water above the sinking Titanic would have had anywhere from several
minutes to an hour to live, depending on their physical condition and how much they flailed. Some
people in the water might have believed that swimming would help their body to generate heat. In
reality, people who swam or moved around a lot would have lost heat 35-50% faster and been
susceptible to exhaustion. There were even several people who died from hypothermia in the
Titanic lifeboats, because they were open and gave no protection against the cold. Regulations
have since been put in place that require lifeboats to be fully or partially enclosed.
Chemical components
1. WATER *75-90% of cell
*good solvent
* high thermal capacity  it can absorb a lot of heat without its t° rising to
dangerous levels As water freezes at 0°C most cells are damaged
2. PROTEINS  STRUCTURAL PROTEINS / ENZYMES
 CHONS molecules made up by long chains of AMINOACIDS
3. LIPIDS  CHO 3 molecules of fatty acids +1 molecule of glycerol
 cell membrane and internal membranes droplets of fat stored in
CYTOPLASM
4. CARBOHY DRATES  *SIMPLE
Monosaccharides (1 single carbon ring)  glucose/fructose
Disaccharides (2 carbon rings) maltose/sucrose
* COMPLEX Polysaccharides
GLYCOGEN/STARCH/CELLULOSE

5. Chemical Process (IN THE CELL)by which ENERGY is produced from FOOD
(GLUCOSE)
5. SALTS : as IONS, take part in chemical reactions/ involved in determining how much water
enters or leaves the cell (OSMOSIS)
6. VITAMINS: *take part in chemical reactions in the cell
*plants produce them/ animals have to obtain them ready- made
Synthesis and conversion in cells
Cells are able to build up or break down CARBOHY DRATES, LIPIDS, PROTEINS
Animal cells CAN change * CARBOHY DRATES to LIPIDS or viceversa
* PROTEINS to CARBOHY DRATES but
CAN’T make PROTEINS unless they receive AMINOACIDS (plants can make their own
starting from sugar and salts)
RESPIRATION
(TISSUE
RESPIRATION)
* AEROBIC FOOD (CHO)+ OXYGEN= OXIDATION *converts *Hydrogen to water
*carbon to carbon dioxide
* sets free ENERGY for contaction of muscle
cells/ active transport/ building up of large molecules/cell division
1st
step In the cytoplasm 1st
GLYCOLISIS  metabolic pathway involving 10 reactions (with
its enzymes) that converts GLUCOSE into PYRUVATE+ free ENERGY (2 ATP+NADH)
ANAEROBIC PROCESS
2nd
step A) If there is O2 =>AEROBIC RESPIRATION IN THE MITOCHONDRIA KREBS CYCLE 
AEROBIC Equation
KJ:It is a derived unit of energy or work in the International System of Units, it’s the amount of E
by completely oxidizing 180 gr of glucose
enzymes
C6H12O6 + 6 O 6CO2+6H2O+ 2830kj / 38 ATP (40% is used and the rest is released as heat)
Glucose oxygen carbon water E
Substrates dioxide

6. CALORY: 1 cal= 4,187 j. It’s not very used now. It expresses the energetic power of food.It’s the
amount of Caloric Energy necessary to increase in 1°C the temperature of 1 gramme of water
ATP: Basic biomolecule of ENERGY used in cell metabolism
B) If there isn’t O2 => ANAEROBIC ReSPIRATION in the cytoplasm  FERMENTATION
(yeats/muscle) (glucose not completely break down)
Respiration in MUSCLES => 1st
ANAEROBIC => produces PYRUVIC ACID (alcohol) => it is
completely oxidized to CARBON DIOXIDE and WATER
Extreme muscular activity => PYRUVIC ACID builds up in a muscle FASTER than it can be
OXIDIZED => it turns into LACTIC ACID => removed into bloodstream => LIVER => In the liver,
gluconeogenesis occurs. It reverses both glycolysis and fermentation by converting lactate first
into pyruvate, and finally back to glucose. The glucose is then supplied to the muscles through the
bloodstream (CORI CYCLE)
Cori cycle While In the anaerobic respiration there is a gain of 2 moles of ATP, there is a
cost of 6 moles of ATP in the gluconeogenesis part of the cycle. => The cycle can’t be
sustained continuously
After exercise =>HIGH LEVEL of O2 consumption PERSISTS until the excess of LACTIC ACID is
oxidized => Volume of O2 needed to complete oxidize the lactid acid : OXYGEN DEBT
Accumulation of Lactic acid causes CRAMPS and MUSCULAR FATIGUE
Disadvantages of ANAEROBIC RESPIRATION: *produces less energy/ produces toxic waste products
(lactid acid)
enzymes
C6H12O6 2C2H5OH+2 CO2+ 118kj
Glucose alcohol carbon E
dioxide

7. BASAL METABOLISM => MINIMUM turnover of energy needed simply to keep an organism ALIVE for
circulation, breathing, body temperature, brain function, chemical processes in the liver (2400 kj)
METABOLISM: chemical reactions Catabolism (respiration)/Anabolism (building up of proteins)
AEROBIC RESPIRATION SIMILARITIES ANAEROBIC RESPIRATION
*USES O2 *E released by breakdown of SUGAR *Don’t use O2
* always produces Carbon
dioxide +water
*ATP made *CO2 sometimes made
*Large amount of E
released
*Some energy lost as HEAT *Small amount of E
released
*ALCOHOL or LACTID ACID
made

8. CELL needs  water/O2/ salts and needs to release CO2 by
DIFFUSION (+  - ) Net movement of molecules from a region of higher concentration
to a region with lower concentration DOWN a concentration gradient as a result od
random movement It depends on * concentration gradient/ thickness of the
membrane/surface area/size of the molecules gases
ACTIVE TRANSPORT movement of IONS in or out of the cell through the cell membrane,
from a region of lower concentration to a region of higher concentration, AGAINST the
concentration gradient, using ENERGY released by respiration
(from - concentration  + concentration) => ENERGY
ENDOCYTOSIS (Phagocytosis and Pinocytosis) - EXOCYTOSIS (form of active transport)
OSMOSIS => diffusion of water molecules from a dilute solution(high water potential) to
a concentrated solution (low water potential) through a partially permeable membrane
* Partially Permeable MEMBRANE*+diluted to +concentrated WATER

9. WATER POTENTIAL quantifies the tendency of WATER to leave a system due to
OSMOSIS/ Gravity or MECHANICAL PRESSURE
+water => +water potential