1.

CELL STRUCTURE AND FUNCTION

Cell Wall
- Only in plant cells, fungi, bacteria
- Rigid, hard, contains cellulose
- Allows nutrients to diffuse in/out of cell, protects

Cell Membrane
- Inside cell wall of plant cells; inside cholesterol of animal cell
- Double membrane, made of phospholipids with proteins
- Selectively permeable. Barrier between environment and cell, maintains homeostasis

Nucleus
- In all cells except prokaryotes (bacteria and archaea)
- Controls all cell activity, holds DNA and hereditary information

Nucleolus
- Inside nucleus
- Can have more than 1; disappears when cell division occurs
- Makes ribosomes

Chloroplast
- Only in plant cells and algae
- Green, oval, contains chlorophyll (green pigment)
- Double membrane with inner membrane modified into sacs (thylakoid). Gel substance
(stroma)
- Performs photosynthesis
- Converts solar energy into chemical energy

Golgi Apparatus
- Modifies proteins made by cells, packages and exports
Centriole
Endoplasmic Reticulum
- Important to cell division
- Smooth, Rough (with ribosomes)
- Only in animals
- Transports materials through cell, helps make protein
- Connected with nuclear envelope and cell membrane

Cytoplasm
- Thick gel, contains cytoskeleton fibers
- Holds all cell organelles, protects

Ribosome
- Small bodies free/attached to endoplasmic reticulum
- Synthesizes proteins

Mitochondrion
- Outer membrane smooth, inner folded into cristae
- Breaks down sugar molecules to produce energy

Vacuole
- Large in plant, small in animal
- Storage
Lysosome
- Breaks down larger food molecules, digests old cell parts

Chromatin
- Found inside nuclear envelope of eukaryotic cells
- Packages DNA into a smaller volume to fit in cell, to strengthen DNA to allow mitosis,

Chromosomes
- A single piece of DNA; Contains many genes
- Made of packed chromatin

Spindle Fibers
- Help in bringing half the chromosomes to polar ends of cell, so when the cell divides,
chromosomes are distributed equally in both the daughter nuclei

HIGHER AMOUNTS
- Mitochondrion – animal cells (plants don’t move and require less energy)
- Golgi complex – plant cells (additional substances to be processed)
- Ribosomes – plant cells
- Lysosomes – animal cells

PLANT CELL VS ANIMAL CELL

- Plant cells have cell walls, animal cells do not
- Plant cells have chloroplasts, animal cells do not
- Plant cell wall is rigid (rectangular shape); animal cell is irregular
- Plant cell vacuoles are large, animal cells are small
2. MITOSIS
Reason for cell division:
- Grow, Reproduce, Repair, Replace

Chromatin vs. Chromosomes:

- Basically the same;
Chromatin = unfolded, uncondensed DNA. Present normally in cells
Chromosomes = condensed DNA. Present only when cell division occurs.

Structure of chromosome

1. Chromatid
2. Centromere – point where two
chromatids touch, where
microtubules attach

Outline of cell cycle

The cell cycle is a series of events that takes place in a cell leading to its division and
duplication. In prokaryotic cells, the cell cycle occurs via a process called binary fission.
In eukaryotic cells, it is called mitosis. The cell division cycle is a vital process by which a
single-celled fertilized egg develops into a mature organism.

Mitosis
1. Interphase:
- To prepare, the DNA replicates
- Cell replicates its centrosome (microtubule organizing centers). One pair per
cell.
2. Prophase:
- Chromatin coils and condenses, resulting in compacted chromosomes
- Nucleolus disappears
- Centrioles begin moving to opposite ends of cell and fibers extend from
centromeres
3. Prometaphase:
- Nuclear membrane dissolves
- Proteins attach to centromeres
- Chromosomes begin moving
4. Metaphase:
- Spindle fibers align the chromosomes along the equator of cell
5. Anaphase:
- Paired chromosomes separate and move of opposite sides of cell
6. Telophase:
 - Chromatids arrive at opposite poles of cell, new membrane forms around the
daughter nuclei
- Chromosomes and spindle fibers disperse

Cytokinesis: a cleavage furrow forms in the center of the cell, and then divides.
3. CELL SPECIALIZATION
Specialized Cells
1. Sperm cell: designed to fertilize eggs. Contains half the chromosomes in the nucleus,
carrying genetic information from father
2. Ovum (egg) cell: designed to be fertilized.
3. Palisade cell: designed for photosynthesis. Found on top side of leaf, large surface
area.
4. Cilia cell: designed to stop lung damage. Lines all the air passages in lungs, tiny hairs
filter the air.

Process used to clone cells

- Somatic cell nuclear transfer
- Laboratory technique for creating a clonal embryo, using an ovum with a donor
nucleus
The nucleus is removed and the rest of the cell discarded. At the same time, the nucleus
of an egg cell is removed. The nucleus of the original cell is insert into the egg cell. The
host cell then reprograms the original cell. The egg cell is stimulated with a shock and
will begin to divide.
- First used on Dolly the sheep in 1996

Potential uses of stem cells and cloning of animal cells

Stem Cells
- To learn more about some serious medical conditions and birth defects to suggest new
strategies for therapy
- Used to test new drugs; new medications can be tested for safety on a wider range of
cell types
- Cell-based therapies; transplantable tissues are in constant demand, and offers the
possibility of a renewable source of replacement cells and tissues to treat diseases

Cloning
- Reviving endangered or extinct species
- Reproducing a loved one or pet
- Help infertile couples have children
- Produce additional crops
- Breed more animals for food
- Clone for organ transplants

CANCER
- Disease of mitosis
- Begins when a single cell is transformed from normal to cancer cell

TUMOUR
- Cancer cell increases rapidly to form mass of cancer cells, tumor
4. LEVELS OF BIOLOGICAL ORGANIZATION
Atom
Molecule
Organelle
Cell
Tissue
Organ
Organ System
Organism

Major Tissues
1. Muscle tissue: bring about movement and mechanical work in various parts of
the body
2. Epithelial tissue: protects underlying tissue, senses, glands secrete certain fluids,
absorbs, excrete (kidney), diffusion, cleaning, reduces friction
3. Nervous tissue: allows organism to sense in both internal and external
4. Connective tissue: provide structural support, nutrients diffuse through tissue to
cells, waste from cells diffuse through

Types of connective tissue

1. Bone
- rigid, hardest tissue
- provides support for muscle attachment and protects internal organs
2. Blood
- 55% plasma, 45% formed elements
- transports substances
3. Cartilage
- strong and flexible
- provides support and cushioning
- found between the discs of the vertebrae in the spine
- surrounds the ends of joints (knees, nose, ears)
4. Fibrous
- provides strength to inner layer of skin and strength to withstand forces of
joint movements
5. Loose
- mass of widely scattered cells
- found beneath skin, in between organs
- binding material which provides support to hold tissues and organis in place

Types of muscle tissue

1. Smooth muscle tissue
- made of thin muscle fibres
- not arranged in a definite striped pattern
- interlace to form sheets
- involuntary, not controlled by brain
- found in walls of hollow organs (stomach, bladder, uterus, blood vessel)
- function: controls slow movement, artery muscles contracts and relax to
regulate blood pressure and flow of blood
2. Skeletal muscle tissue
- Most abundant
- arranged in a definite striped pattern
 - cause the movement of various bones of skeleton
- function: pairs coordinate movements of limbs, directly involved in the
breathing process
3. Cardiac muscle tissue
- only found in the walls of the heart
- shows some characteristics of smooth and skeletal
- fibres are like skeletal
- involuntary like smooth muscle
- functions: plays an important role in the contraction of the atria and
ventricles of the heart, causes the beating of the heart, circulates the blood

Organs
1. Kidney
- excretes waste products produced by metabolism
- regulates bicarbonate concentration and acids
- long-term regulation of blood pressure
- secretes variety of hormones
2. Lungs
- transport oxygen from the atmosphere into the bloodstream
- release carbon dioxide from bloodstream into the atmosphere
3. Skin
- protects. Acts as a barrier from external environment
- contains nerves that can sense heat, cold, touch, pressure, vibration, tissue
injury
- iregulates heat
- control of evaporation
- acts as storage for lipids and water
- absorbs
- water resistant

Nervous System
- Coordinate the actions and transmit signals between parts of body
- Central: brain, spinal cord, retina
- Peripheral: sensory neurons, nerves

Endocrine System
- System of glands, each of which secrete a hormone into blood to regulate the
body
- Information signal system
- Important for growth of body and sexual development

Urinary System
- Produces, stores, and eliminates urine
- Includes two kidneys, two ureters, the blatter, urethra, two sphinctermuscles
- Flushes out all toxins from body

Adipose Cell
- Fat cell, connective cell specialized to synthesize and contain large amounts of fat
Neuron
- Cell that processes and transmits info by electrical and chemical signaling
- Core component to nervous system
5. HUMAN DIGESTIVE SYSTEM
Function
To break down food we eat into smaller parts so the body can build and nourish cells to
provide energy

Digestive System (steps)

1. MOUTH: continual movement of incisors, molars crush, salivary enzymes, soft palate
pushes food into pharynx
2. ESOPHAGUS: mouth to stomach, peristalsis forces food to stomach
3. STOMACH: sphincter muscle opens up, food goes to stomach, sphincter muscle
contracts, gastric acid changes food into liquid
4. SMALL INTEST: chyme enters duodenum, pancreatic juices, bile (produced in liver
and stored in gall bladder), enters jejunum then ileum
5. LARGE INTEST: water and electrolytes removed, enters (cecum, ascending colon,
across abdomen, transverse colon, descending colon)
6. ANUS: rectum contracts, expelling waste
Polymer vs Monomer
Monomer:
- single structure
- low molecular weight

Polymer:
- several monomers
- higher molecular weight

Physical vs Mechanical Digestion

Physical – when material being digested is broken down by mechanical means, like
chewing food using teeth and tongue. The stomach uses muscular movement to mix and
continue this breakdown.

Mechanical – when material being digested is acted upon by enzymes to speed up the
molecular breakdown. Salivary amylases begin the chemical breakdown.

Function of enzyme
- Fastens reactions in
- Called ‘catalysts’ because they speed up reaction by lowering the amount of
energy needed to start the reaction

Amylase, Protease, Lipase

1. Amylase
- breaks down starch into sugar
- present in human saliva
- begins the chemical process of saliva
2. Protease
- protein-digesting enzyme
- produced in stomach, pancreas, salivary gland, small intestine
3. Lipase
- break down lipids (fat and oils)

Peristalsis
- Symmetrical contraction and relaxation of muscles, only moves in one
direction
- Found in contraction of smooth muscles to propel contents through the
digestive tract
- Occurs in esophagus and small intestine
- Esophagus: after food is chewed, it is swallowed through esophagus. Smooth
muscles contract to prevent it from being squeezed back into the mouth,
then waves of contractions work rapidly to force the food into the stomach
- Small intestine: once processed and digested in stomach, the chyme is
squeezed through into the small intestine. The wave will occur to mix the
chyme in the intestine. During this process digestion continues and the body
also absorbs nutrients.

Liver, Gall Bladder, Pancreas

1. Liver
- to process nutrients absorbed from small intestines
 - bile secreted from liver digests fat
2. Gall Bladder
- stores and concentrates bile, then releases it into duodenum to help absorb and
digest fats
3. Pancreas
- secretes digestive enzymes into duodenum
- enzymes break down protein, fats, carbohydrates
- pancreas makes insulin, secreting it into bloodstream (metabolizes sugar)

Gastric Juices, Bile, Pancreatic Juices

1. Gastric juices
- digestive enzymes digest proteins
- make ingested proteins unravel so that enzymes can break down the acids
2. Bile
- bile breaks down fat and cholesterol
- waste elimination
3. Pancreatic juices
- enzymes complete digestion of starch
- carry out half of protein digestion
- fat digestion

Structure of Villus
- Villi increases the surface area of intestinal wall, so more is absorbed
- Useful because digested nutrients pass into the villi through diffusion
- Increased surface area = less distance, so effectiveness of diffusion increases
- More food can be absorbed
6. HUMAN TRANSPORT SYSTEM (CIRCULATORY)
Function
- Passes nutrients, hormones, etc. from cells to help fight disease and stabilize body
temperature to maintain homeostasis

Main components
- Heart, Arteries, Capillaries, Veins

Arteries, Veins, Capillaries

1. Arteries
- muscular blood vessels that carry oxygenated blood away from heart
- tough on outside, smooth inside. 3 layers
2. Veins
- blood vessel channels that carry waste-rich blood back to lungs and heart
- 3 layers, thinner and contain less tissue than arteries. Valves inside.
3. Capillaries
- receives oxygen-rich blood from arteries, exchanges oxygen and CO2 and
then delivers waste-rich blood to veins
- thin, fragile blood vessels. Only 1 epithelial cell thick.

Human Heart (diagram)

Flow of blood through the heart

1. Oxygen-deprived blood returns to heart via the superior and inferior vena cava
2. Enters right atrium, flows through tricuspid valve into right ventricle, pushes
through pulmonary valve into pulmonary artery
3. Carries blood to lungs, returns to heart through pulmonary vein. Blood enters
left atrium, through mitral valve. Pumps through aortic valve, into aorta.
Atria, Ventricles
1. Atria
- right atria: collect blood from head or body
- left atria: collect blood from lungs
2. Ventricle
- right ventricle: pumps blood to lungs
- left ventricle: pumps blood from heart to rest of body

Left & Right of Heart

Left:
- Receives oxygenated blood
- Thicker because of requirement to pump blood

Right:
- Receives deoxygenated systemic blood from superior and inferior vena cava

Function of valves in the heart

1. Two atrioventricular valves
- Prevents backflow
2. Two semilunar valves
- Permits blood to be forced into arteries, but prevent backflow

Role of coronary circulation

- Circulation of blood in blood vessels of heart muscle
- Keeps the heart muscle strong and healthy through oxygen exposure and blood
distribution

Coronary artery diseases

1. Atherosclerosis
- artery wall thickens as result of fat buildup
- it is a syndrome affecting arterial blood vessels

Medical imaging technologies in the diagnosis of heart disease

- magnetic resonance imaging (MRI)
- uses powerful magnetic field, radio frequency pulses, and computer
- produces detailed pictures of all internal structures
- evaluates anatomy and function of heart

Treatments for Coronary Artery Disease

1. Lifestyle change:
- exercise, healthy diet
2. Angioplasty
- mechanically widening a narrowed or obstructed blood vessel
- a balloon catheter is passed and inflated, crushing fatty deposits
3. Stent
- tube placed in coronary arteries to keep artery open
- used in procedure called Percutaneous Coronary Intervention
- reduces chest pain, but not shown to improve survival
4. Coronary artery bypass graft
- arteries from elsewhere in body is grafted to the coronary artery
- improve blood supply
 - surgery performed with heart stopped

Procedures in Coronary Artery Bypass Graft

1. Injects painkilling, then induction agent
2. Chest opened via median sternotomy and heart examined by surgeon
3. Bypass grafts are harvested. Patient given heparin to prevent blood clotting
4. Surgeon places device to stabilize heart
5. One end of graft is sewn on the coronary arteries beyond the blockages and other end
is attached to aorta
6. Stabilizing device removed