TEAS Test Study Guide for Science.
● Mitosis = “daughter cell” exact replica
o Interphase (G1, S,
... [Show More] G2)
o Prophase
o Metaphase
o Anaphase
o Telophase
o Cytokinesis
Cell Cycle
● Meiosis = “daughter cells” different genetic coding
o Only happens in gametes*
o 1st phase
● chromosomes cross over
● genetic material exchanged
● tetrads of 4 chromatids formed
□ Homologous pairs of chromatids are separated and go to different poles
□2 cells go through 2nd cell division
□ 4 daughter cells with different sets of chromosomes
● Haploid : contains half genetic material of parent cell
● Zygote- controls cell differentiation
Tissues
¾ groups of cells
¾ Muscle, nerve, epithelial, connective
1. Epithelial: (joined together tightly) ex. Skin
2. Connective: (dense, loose, or fatty) ex. Bone tissue, cartilage, tendons, ligaments, fat, blood, lymph
□Protects & binds body parts
a. Cartilage: cushions & provides structural support
i. Fibrous
b. Blood: transports oxygen to cells & removes waste / ALSO carries hormones & defends against disease
c. Bone: (hard) produces red blood cells
3. Muscle: Support & move body
a. Smooth
b. Cardiac
c. Skeletal
4. Nervous: ex. Brain, spinal cord, & nerves
a. Neurons- control responses to changes in environment
Organs
¾ groups of tissues
ex. Heart = muscle tissue in myocardium; connective tissue in blood; nervous tissue for heart rate; epithelial tissue in membranes
Organ Systems
¾ groups of organs
1. Integumentary (Exocrine system)
a. Skin
i. Sebaceous glands sweat glands
ii. Hair
iii. Nails
b. Protection
i. Protects body from pathogens
c. Secretion
i. Secrete oil
d. Communication
i. Sensory receptors send info. about pain, touch, pressure, and temperature
LAYERS OF THE SKIN
1. Epidermis
a. Most superficial layer of skin
b. Epithelial cells **Does not contain any blood vessels
c. Stratum basale
i. deepest portion
ii. single layer of cells
iii. keratinized
1. waxy protein waterproofs skin
2. Dermis
a. Mostly connective tissue
b. Blood vessels, sensory receptors, hair follicles, sebaceous glands, sweat glands
c. Elastin and collagen fibers
3. Subcutaneous layer/ Hypodermis
a. Connective tissue
i. Binds skin to muscle
b. Fat deposits cushion and insulate TEMPERATURE HOMEOSTASIS
¾ skin is involved in temperature homeostasis through sweat glands
a. Controlled by negative feedback system
a. Receptor
i. Sensory cells in dermis of skin
b. Control center
i. Hypothalamus
c. Effector
i. Sweat glands, blood vessels, and muscles (shivering)
ii. Evaporation of sweat cools body
iii. Vasodilation of blood vessels release heat into environment to lower body temperature
SEBACEOUS VS SWEAT GLANDS
a. Both exocrine glands
a. Secrete substances into ducts
i. Through ducts to the surface of the skin
1. Sebaceous glands
a. Holocrine glands
i. Secrete sebum
1. Oily mixture of lipids and proteins
b. Connected to hair follicles and secrete sebum through hair pore
1. Sweat glands
a. Eccrine or apocrine glands
i. Eccrine glands: not connected to hair follicles
1. Secrete salty solution
2. Forehead, neck, back
3. Activated by elevated body temperature
ii. Apocrine glands
1. Secrete oily solution
2. Armpits, groin, palms, soles of feet
3. Activated by stress or anxiety
2. Respiratory
a. Structure
i. UPPER: Nose, nasal cavity, mouth, pharynx (throat), larynx (voice box)
ii. LOWER: trachea (windpipe), lungs, bronchial tree
iii. Airway: lined with cilia that sweep debris back towards mouth
iv. Lungs: (bronchi & bronchial network ---alveoli)
v. RIGHT LUNG: 3 lobes
vi. LEFT LUNG: 2 lobes
vii. MUSCLES
1. Diaphragm
a. Dome-shaped
b. Separates thoracic & abdominal cavities
2. Intercostal muscles
a. Between ribs
b. Function
i. Supply body w/ oxygen by alveoli
ii. Filters air (warmed, moistened, & filtered before reaching lungs) iii. Speech (air moves through larynx □ produces sound □ trachea iv. Smell
1. Chemoreceptors (in nasal cavity) respond to chemicals v. BREATHING PROCESS (controlled by medulla oblongata)
1. Diaphragm & intercostal muscles expand □increase size of chest cavity 2. Volume chest cavity increases = pressure inside decreases
3. Outside air (high pressure); Air in lungs (low pressure) □ air goes in lungs 4. Muscles relax □ air leaves lungs
3. Cardiovascular
● BLOOD
o Red blood cells
▪ Transport oxygen to cells
▪ Form in bone marrow
o White blood cells
▪ Defend against infection
● Lymphocytes
● Neutrophils
● Monocytes
● Eosinophils
● Basophils
o Platelets
▪ Blood clotting
o Plasma
▪ half blood volume
▪ mostly water/ serves as a solvent
▪ contains plasma proteins, ions, glucose, amino acids, hormones, & dissolved gas
● BLOOD VESSELS
● HEART
o 4 chambers
▪ each half = atrium & ventricle
● AV valve separates halves
o between ventricle & artery leading away from heart
● keep blood moving in single direction
o Cardiac cycle
▪ Atrial contraction = fills ventricles
▪ Ventricular contraction = empties ventricles
▪ 1st DIASTOLE PHASE
● Blood flows through superior & inferior venae cavae
● (heart relaxed) atrium □ tricuspid valve □ right ventricle
● SA node (pacemaker wall of right atrium) generates signals (carried by Purkinje fibers) to rest of atrium
● Contracts & fills right ventricle w/ blood
● Impulse from SA node transmitted to ventricle through AV node
● Signals the right ventricle to contract & initiate 1st systole phase
▪ 1st SYSTOLE PHASE
● Tricuspid valve closes□ Pulmonary semilunar valve opens
● Blood is pumped out the pulmonary arteries to lungs
▪ 2nd DIASTOLE PHASE
● Blood returning from lungs fills left atrium
● SA node triggers mitral valve to open □ Blood fills left ventricle
▪ 2nd SYSTOLE PHASE
● Mitral valve closes □ Aortic semilunar valve opens
● Left ventricle contracts □ blood is pumped out of aorta to rest of body
o Types of Circulation
▪ Coronary: Flow of blood to heart
● Coronary arteries □ aorta (supplying major arteries) □ enter heart w/ oxygenated blood
● Deoxygenated blood returns to right atrium through cardiac veins (empty into the coronary sinus)
▪ Pulmonary: flow of blood between the heart & lungs
● Deoxygenated blood flows from right ventricle to the lungs through pulmonary arteries
● Oxygenated blood flows back to the left atrium through pulmonary veins
▪ Systemic: flow of blood to entire body
● blood exits left ventricle through aorta □ branches into the carotid arteries, subclavian arteries, common iliac arteries, & renal artery
● blood returns to heart through jugular veins, subclavian veins, common iliac veins, & renal veins □ empty into superior & inferior venae cavae
o Portal circulation: flow of blood from digestive system to the liver & then back to the heart
o Renal circulation: flow of blood between the heart & kidneys
o Blood Pressure
¾fluid pressure generated by the cardiac cycle
▪ Functions by transporting oxygen-poor blood into the lungs & oxygen-rich blood to body tissues
▪ Arteries branch into smaller arterioles which contract & expand based on body signals
▪ Arterioles are where adjustments are made in blood delivery to specific areas based on complex communication from body systems
● Capillary beds: diffusion sites for exchanged between blood and interstitial fluid
o has the thinnest wall of any blood vessel (single layer endothelial cells)
4. Endocrine
¾secrete hormones that help regulate body
a. Endocrine system and nervous system work closely together
i. Hypothalamus + pituitary gland = neuroendocrine control center
ii. MAJOR ENDOCRINE GLANDS
1. Adrenal cortex
a. Monitors blood sugar level
b. Helps in protein & lipid metabolism
2. Adrenal medulla
a. Controls cardiac function
b. Raises blood sugar
c. Controls size of blood vessels
3. Thyroid gland
a. Regulate metabolism
b. Functions in growth/development
4. Parathyroid
a. Regulates calcium levels in blood
5. Pancreas islets
a. Raises and lowers blood sugar
b. Active in carbohydrate metabolism
6. Thymus gland
a. Role in immune responses
7. Pineal gland
a. Influence on daily biorhythms and sexual activity
8. Pituitary gland
a. Growth and development
ENDOCRINE FUNCTIONS OF PANCREAS
a. Islets of Langerhans
i. groups of endocrine cells
ii. insulin-producing beta cells and glucagon-releasing alpha cells
b. Hormones (pancreas)
i. Insulin
1. Control carbohydrate metabolism
a. Lowering blood sugar
2. Affects fat metabolism
ii. Glucagon
1. Control carbohydrate metabolism
a. Increase blood sugar THYROID & PARATHYROID GLANDS
a. Parathyroid glands
i. 4 small glands
ii. secrete parathyroid hormone
1. increase blood calcium
b. Thyroid gland
i. regulate metabolism
ii. secretes
1. Thyroxine
a. Increase metabolism
2. Triiodothyronine
a. Increase metabolism
3. Calcitonin
a. Decreases blood calcium
c. Hypothalamus
i. directs pituitary gland to secrete TSH
1. stimulates the thyroid gland to release these hormones as needed
5. Nervous
□ senses, interprets, and issues commands as a response to conditions in a body’s environment
● Action potential: messages are sent across the plasma membrane of neurons
o Occurs when neuron is stimulated past threshold
o Chemical synapse: point of contact
▪ substance is released that stimulates or inhibits the actions of adjoining cell
▪ this forms the framework for the nervous system
● FUNCTIONAL TYPES OF NEURONS
o 1. Sensory neurons
▪ transmit signals to the central nervous system
● associated with touch, pain, temperature, hearing, sight, smell, & taste
o 2. Motor neurons
▪ transmit signals from the CNS to the rest of the body
● signal muscles or glands to respond
o 3. Interneurons
▪ transmit signals between neurons
● Neuron Parts
o 1. Cell body (soma)
▪ contains nucleus of neuron
o 2. Axon
▪ transmits impulses away from cell body
▪ insulated by oligodendrocytes & myelin sheath with gaps (nodes of Ranvier)
▪ terminates at the synapse
o 3. Dendrites
▪ receive impulses from sensory receptors or interneurons & transmit them toward cell body
PRIMARY COMPONENTS OF CNS
Spinal Cord
● encased in the vertebrae
o protects & supports spinal cord
● nervous tissue functions mainly with respect to limb movement and internal organ activity
Brain (2 hemispheres / 4 main lobes)
Consists of
1. Hindbrain
● medulla oblongata
● cerebellum
o processing & storing implicit memories
▪ memories developed during classical conditioning
▪ ex. Response to a puff of air into the eyes
● pons
2. Midbrain
¾integrates sensory signals & makes responses to them
3. Forebrain
● cerebrum
o cerebral cortex
▪ thin layer of gray matter covering cerebrum
● thalamus
● hypothalamus
Brain Stem (connected to spinal cord)
* information from the body is sent to the brain through the brain stem
* information from the brain is sent to the body through the brain stem
1. Midbrain
● lies above the pons & the medulla oblongata
● Parts include
o Tectum
o Tegmentum
o Central tegmentum
● Important part of vision & hearing
2. Pons
● Between midbrain & medulla oblongata
● Information is sent across the pons from the cerebrum to the medulla & the cerebellum
3. Medulla oblongata
● Beneath the midbrain & pons
● Connects spinal cord to the brain
● Important role with autonomous nervous system in circulatory & respiratory system
**Peripheral nervous system consists of the nerves & ganglia throughout the body & includes sympathetic nerves which trigger the “fight or flight” response, and the parasympathetic nerves which control basic body function
Four main lobes
1. Frontal lobe
● located at the front of the brain
● Responsible for
o short term & working memory
o information processing
o decision making, planning, judgment
2. Parietal lobe
● slightly towards the back of the brain & the top of the head
● Responsible for
o Sensory input
o Spatial positioning of the body
3. Occipital lobe
● Located at the back of the head just above the brain stem
● Responsible for
o Visual input, processing, and output
▪ Specifically nerves from eyes enter directly to this lobe
4. Temporal lobe
● Located at the left and right sides of brain
o Responsible for
▪ Auditory input, processing, and output Autonomic Nervous System (ANS)
¾ maintains homeostasis within the body
(regulate heart rate, breathing rate, body temperature, & blood pH
● controls functions of internal organs, blood vessels, smooth muscle tissues, & glands
o this accomplished through direction of hypothalamus
▪ located above midbrain
▪ controls ANS through the brain stem
● 2 divisions
o 1. Sympathetic Nervous System
▪ controls body’s reaction to extreme, stressful, & emergency situations
● increases heart rate □ signals adrenal glands □ triggers dilation of pupils □ slows digestion
o 2. Parasympathetic Nervous System
▪ counteracts effects of the sympathetic nervous system
Somatic Nervous System (SNS) & the Reflex Arc
¾controls the 5 senses & voluntary movement of skeletal muscle
● all neurons connected to sense organs
o Efferent nerves
▪ Motor
▪ Efferent muscles bring signals from the CNS to sensory organs & muscles
o Afferent nerves
▪ Sensory
▪ Afferent muscles bring signals from sensory organs & the muscles to the CNS
● Reflex Arcs: involuntary movements
o Simplest nerve pathway
▪ Bypasses the brain & is controlled by the spinal cord
6. Immune System (Lymphatic System & red bone marrow and leukocytes)
a. Return excess tissue fluid to bloodstream
i. Transport vessels & lymphoid organs
ii. Lymphoid organs
1. Lymph nodes
a. located at intervals throughout lymph vessel system
b. each node contains lymphocytes & plasma cells
2. Spleen
a. Filters blood stores of red blood cells & macrophages
i. Help fight infections
b. Upper left of abdomen
i. Behind stomach & immediately below diaphragm
ii. Made of lymphoid tissue
c. Blood vessels are connected to spleen by splenic sinuses
d. Peritoneal ligaments support spleen
i. Gastrolienal ligament
1. Connects stomach to spleen
ii. Lienoral ligament
1. Kidney to spleen
iii. Middle section of phrenicocolic ligament
1. Left colic flexure to thoracic diaphragm
3. Appendix
4. Adenoids
5. Thymus
a. Secretes hormones
b. Major site of lymphocyte production
6. Tonsils
7. Small patches of tissue in small intestine
iii. Vascular system: lymph capillaries, lymph vessels, lymph ducts
1. FUNCTIONS
a. Return excess fluid to blood
b. Return protein from capillaries
c. Transport fats from digestive tract
d. Disposal of debris & cell waste
□ protects the body against pathogens
● tissue fluid enters lymph capillaries □ combine to form lymph vessels □ skeletal muscle contractions move lymph one way through lymphatic
system to lymphatic ducts □ dump back into venous blood supply into lymph nodes (neck, armpits, groin)
● Lymphatic tissue: tonsils, adenoids, thymus, spleen (cleans blood), Peyer’s patches (in small intestine- protect digestive system)
IMMUNE DEFENSES
● Skin
● Ciliated Mucous Membranes
o Cilia sweep pathogens out of respiratory tract
● Glandular Secretions
o Secretions from exocrine glands destroy bacteria
● Gastric Secretions
● Normal Bacterial Populations
TYPES OF WHITE BLOOD CELLS (contribute to body’s defense)
● Macrophages
o Phagocytes that alert T cells to the presence of foreign substances
● T Lymphocytes
o Directly attack infected cells
● B Lymphocytes
o Target specific bacteria
TYPES OF LEUKOCYTES (these are produced in red bone marrow)
● Classified as
o Monocytes
▪ Macrophages
● Travel in lymph / fixed in lymphatic tissue
● Largest phagocytes that engulf pathogens
▪ Dendritic cells
● Present antigens to T cells
o Granulocytes
▪ Neutrophils
● Short-lived phagocytes that respond quickly
▪ Basophils
● Alert body of invasion
▪ Eosinophils
● Large, long-living phagocytes
o T lymphocytes
▪ Helper T cells
● Produce antibodies to help fight infections
▪ Killer T cells
● Destroy infected cells
▪ Suppressor T cells
● Stop other T cells when over
▪ Memory T cells
● Remain in blood incase invader attacks again
o B lymphocytes
▪ Produce antibodies
o Natural killer cells
ANTIGEN & IMMUNE RESPONSE
● Antigen
o Stimulate immune system
o Proteins on surfaces of bacteria, viruses, & fungi
● Typical Immune Response
o Pathogen enters body □ engulfed by macrophage □ killer T cells & B cells activated
▪ Killer T cells- search out & destroy cells w same antigens
▪ B cells- differentiate into plasma and memory cells
● Plasma cells
o Produce antibodies specific to pathogen □
Antibodies bind to antigens on the surface of pathogens & mark them for destruction by other phagocytes
● Memory cells
o Remain in blood stream to protect against future infections
7. Digestive
MOUTH & STOMACH
a. Digestion: Mouth (chewing/ saliva) □ pharynx □ esophagus □ stomach
i. Stomach
1. Mixing/ storing food
2. Dissolving/ degrading food
3. Control passage of food into small intestine
a. Stomach acidity breaks down food □ makes nutrients available for absorption
b. Peristalsis: contracts & relaxes to move nutrients into small intestine □ absorption process begins
ii. Liver
1. Largest solid organ/ largest gland (3 pounds)
2. Below diaphragm on right side of chest
3. 4 lobes
a. Right
b. Left
c. Quadrate
d. Caudate
4. Secured to diaphragm & abdominal walls by 5 ligaments
a. falciform
i. forms a membrane-like barrier between right & left lobes)
b. coronary
c. right triangular
d. left triangular
e. round
5. Processes all of the blood that passes through digestive system
a. Nutrient-rich blood □ liver (via hepatic portal vein) □ leaves liver (via hepatic veins)
i. Hepatic artery supplies oxygen-rich blood
6. Functional units: lobules
a. Made up of layers of liver cells
7. FUNCTIONS
a. Production of bile, blood plasma proteins, cholesterol
b. Storage of excess glucose in form of glycogen
c. Regulation of amino acids
d. Processing of hemoglobin (to store iron)
e. Conversion of ammonia (that is poisonous) to urea
f. Purification of blood (clears out drugs/ toxins)
g. Regulation of blood clotting
h. Control infections by boosting immune factors & removing bacteria
iii. Small Intestine
1. Most nutrients are absorbed in small intestine
2. Bile: secretion of the liver
a. Useful in breaking down fats
b. Stored in gall bladder between meals
c. When food reaches the lining of the small intestine it has been reduced to small molecules
d. Lining of small intestine
i. Covered with villi
1. Increase surface area for interaction with chime
ii. Microvilli
iv. Large Intestine
1. Also called the colon
2. Concentrates, mixes, & stores waste
3. Secretes enzymes to small intestine that help break down foods
4. Secretes secretes sodium bicarbonate to neutralize stomach acid
5. Muscle sphincter at end of anus facilitates expelling of waste matter
v. Pancreas
1. Head: near duodenum
2. Tail: near spleen
3. Exocrine tissue
a. Secretes digestive enzymes
b. Main pancreatic duct- connects to the common bile duct near duodenum
c. Controlled by hormones released by stomach and duodenum when food is present
d. Secretions flow into main pancreatic duct (Wirsung’s duct) & are delivered to duodenum through pancreatic duct
4. Endocrine tissue
a. Secretes hormones (insulin) into bloodstream
8. Excretory (Urinary System)
Consists of…
● Kidneys (filter blood, reabsorb needed materials, & secrete wastes and excess water in urine
o Renal cortex
▪ Outer layer
▪ Composed of a million nephrons
● Tiny, individual filters of kidneys
● Each contains cluster of capillaries called a glomerulus (filters blood) surrounded by the Bowman’s capsule which leads to a tubule
o Renal medulla
▪ Inner layer
o Renal pelvis
▪ Innermost portion
● Urinary ducts
● Bladder
o Urine is drained from kidneys □ through ureters □ to bladder □ urethra
9. Muscular
● Skeletal
o Voluntary muscles
o Composed of muscle fibers (parallel bundles)
o Striated
o Consists of muscle fibers
▪ Contains bundle of myofibrils
● Contractile units called sacromeres
● Contain 2 protein microfilaments
o Thick filament
▪ Protein myosin
o Thin filament
▪ Protein actin
▪ when an electrical signal reaches a muscle fiber □calcium ions are released
● Cardiac
o Involuntary muscle
o Heart
o Striated
● Smooth
o Involuntary muscle
o Walls of internal organs
▪ Stomach
▪ Intestines
▪ Blood vessels
o Nonstriated
**ALL muscles
● Excitability: have electric gradient which can reverse
● Contraction: ability to contract (shorten)
● Elongate: elongate (relax)
10. Skeletal
● Bones & cartilage
● Axial skeleton
o Skull, sternum, ribs, and vertebral column
● Appendicular skeleton
o Bones of arms, feet, hands, legs, hips, and shoulders
● Functions
o Movement
o Mineral storage
o Support
o Protection
o Blood Cell Formation
▪ Red blood cells are produced in the marrow
● Classified as…
o Long
o Short
o Flat
o Irregular
● Connective bone tissue
o Compact bone
▪ Tightly packed cells
▪ Strong, dense, and rigid
▪ Haversian cells (Haversian system provides reservoir for calcium & phosphorus for the blood)
● Surrounded by bone tissue called lamellae
o Spaces between is lacunae
o Spongy bone
▪ Trabeculae
● Network of girders with open spaces filled with red bone marrow
● Lightweight and porous
11. Reproductive
Male
Female
● Functions include
o Produce, maintain, transfer sperm and semen, produce & secrete male hormones
● External structure
o Penis
▪ Urethra
o Scrotum
▪ Houses testes
▪ Keeps testes at proper temperature for spermatogenesis
o Testes
▪ Male gonads
▪ Produce sperm and testosterone
● Internal structure
o Epididymis
▪ Stores sperm as it matures
▪ Mature sperm □ epididymis□vans deferens□ejaculatory duct
o Vans deferens
o Ejaculatory ducts
o Urethra
o Seminal vesicles
o Prostate gland
▪ Secretes milky white fluid with proteins and enzymes as part of semen
o Bulbourethral gland
▪ Also called Cowper’s glands
▪ Secrete fluid into urethra to neutralize acidity in the urethra
● Hormones include
o Follicle-stimulating hormone
▪ Stimulates spermatogenesis
o Luteinizing hormone
▪ Stimulates testosterone production
o Testosterone
▪ Male sex characteristics
● Produce ova (oocytes, egg cells), transfer the ova to fallopian tubes for fertilization, receive sperm, & provide a protective, nourishing environment for embryo
● External structure
o Labia major
o Labia minor
▪ Protect vagina
o Bartholin’s glands
▪ Secrete lubricating fluid
o Clitoris
▪ contains erectile tissue and nerve endings
● Internal structure
o Ovaries
▪ Female gonads
▪ Produce ova
▪ Secrete estrogen and progesterone
o Fallopian tubes
▪ Carry mature egg toward uterus
▪ Fertilization occurs here
o Uterus
▪ Fertilized egg travels here & implants in uterine wall
▪ Protects embryo
o Vagina
▪ Provide birth canal
Body Planes
● Transverse = horizontal (superior/inferior)
● Sagittal = vertically right & left; parallel to midline
● Coronal = frontal; vertically front & back (anterior/ posterior)
Direction
● Medial: near midline (EX. Little finger is medial to thumb)
● Lateral: away from midline (EX. Thumb is lateral to little finger)
● Proximal: center of body (EX. Hip is proximal to knee)
● Distal: away from center (EX. Knee is distal to hip)
● Anterior: front
● Posterior: behind
● Cephalad: towards head
● Caudad: towards posterior
● Superior: above (closer to head)
● Inferior: below (closer to feet)
***specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C
Calculating population change
(# births/time period) / population size *1000
P.E. = mgh
m = mass in kilograms
g = acceleration due to gravity (9.8 m / s2 at the surface of the earth) h is the height in meters.
kinetic energy, kg m2 / s2
**periodic table Khan Academy
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1. Alkanes - Are saturated hydrocarbons that therefore contain only hydrogen and carbon atoms bonded to each other, and typically follow the chemical formula CnH2n+2. A common example is paraffin.
2. Alkenes - These unsaturated hydrocarbons are molecules that contain at least one
carbon-to-carbon double bond. With the chemical formula consisting of molecules of CnH2n, alkenes are very common in the petrochemical industry; the simplest alkene is ethylene, or ethane.
3. Alkynes - This category of hydrocarbons are unsaturated, and contain at least one carbon-to-carbon triple bond. The hydrophobic acetylenes are common examples of alkynes.
4. Cycloalkanes - The saturated hydrocarbons not only form only carbon-to-hydrogen bonds, rather than the carbon-to-carbon bonds that have to then have added hydrogen atoms. These alkanes have to prefix "cyclo" due to the configuration of rings of carbon atoms in their structure.
5. Aromatic hydrocarbons - These unsaturated hydrocarbons have alternating carbon-to-carbon single or double bonds in their molecules. The term aromatic was applied to this category of hydrocarbons before the chemical nature of aromaticity was discovered, and they were therefore called aromatic simply because these compounds had a pleasant smell.
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