Animals part 2 Flashcards
Metabolism
set of chemical reactions that occur in living organisms that are necessary to maintain life
Catabolism
metabolic reactions that break down larger molecules into smaller units (digestion)
Anabolism
metabolic reactions that use energy to produce larger molecules from smaller subunits (building muscle)
Basal Metabolic rate
The rate at which energy is used by an organism when at rest
Factors affecting Basal Metabolic Rate
Body size: the larger the body, the more energy is required to stay alive
Physical activity: muscles burn more energy than fat, so physical activity requires more energy
Sex: Males are typically larger in size, and have a greater proportion of muscle mass than females of the same size, age and fitness
Age: metabolic rate decreases with age
Heredity factors: some individuals naturally have higher or lower metabolic rates
Carbs
Major source of energy for all body function
Excess carbohydrates in the body are stored as glycogen in the liver and muscle, but they can also be stored as fats if glycogen storage is full
Cellulose
Polysaccharide found in plants
Cannot be broken down by humans and therefore has no nutritional value
Also known as fiber
Aids in movement of food through digestive system
Proteins
Made up of combinations of 20 different amino acids, joined by peptide bonds
Important roles: Enzymes Hormones (chemical messengers) Transporting oxygen (hemoglobin in red blood cells) Structures (muscles, hair, nails) Antibodies in blood
Fats/Lipids
Concentrated source of energy (1 g = 38kJ) twice as much energy as proteins and carbohydrates
Many important roles in the body
Lipids in the cell membrane maintain fluidity
Protection around organs and joints
Surround nerve cells to increase speed of nerve impulse
Insulates body
Vitamins
Most act as coenzymes, binding to enzymes to ensure proper function
Two types of vitamin : fat soluble and water soluble
Fat soluble are stored in the body’s fatty tissue for later use and cannot be eliminated
Water soluble cannot be stored in the body and are easily excreted in urine and sweat, that must be replenished every day through diet
Minerals
Used for a variety of functions:
→ Iron in hemoglobin
→ Calcium in bones and teeth
Main source of minerals are plants, but we get some from meat
Excess minerals are lost in sweat and urine
Enzymes
specialized proteins that act as biological catalysts - they speed up chemical reactions
Function of Digestive System
Digestion is the process of making food absorbable by dissolving it, and breaking it down into simpler chemical compounds.
This is done mainly through the action of enzymes (amylase) secreted into the alimentary canal (one long, continuous tube).
Describe the 2 phases of digestion
1.Mechanical breakdown of the food into smaller pieces to increase the surface area.
Chew, tear, grind, mash, mix
2. Chemical breakdown
Enzymatic reactions to improve digestion of carbohydrates, proteins and lipids
peristalsis
Moves food bolus to stomach through involuntary muscle contractions
Epiglottis
covers the end of the trachea when swallowing
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Liver
Synthesis of bile (fat digestion) Two lobes Regulates body metabolism Removes toxins from body Excessive alcohol results in liver disease (Cirrhosis)
Pancreas
Releases bicarbonate ions to neutralize chyme
Secretes enzymes: lipase, carbohydrase, protease, nuclease
Also secretes insulin to aid in glucose absorption in cells
Gallbladder
Concentrates and stores bile received from liver Sends bile through bile duct to duodenum to mix with chyme Bile emulsifies (breaks down) fat and aids in lipid absorption
External Respiration
Exchange of gases between alveoli and the blood
O2 diffuses INTO the organism (blood)
CO2 diffuses OUT of the organism (lungs)
The lung surface is LARGE and moist
Internal Respiration
Exchange of gases between the blood in capillaries and individual cells
O2 diffuses INTO the cells
CO2 diffuses OUT of the cells
Internal respiration takes place in the tissues.
External respiration occurs in the lungs.
Cellular Respiration
The breakdown of sugar molecules into usable energy molecules (ATP)
Occurs in the mitochondria
Requires the presence of O2
Results in the production of CO2
Pharynx
Area at the back of the mouth that acts as a common path for both food and air
Branches into two pipes:
Esophagus: leads to stomach
Trachea: leads to lungs
Larynx
Also known as the voice box
Made up of several pieces of cartilage
Sounds are produced by vibrations of the vocal cords and vibrations in the air as it passes through the larynx and out the mouth
Cilia
sweep mucus and trapped particles up and out of the trachea
Alveoli
The smallest bronchioles end in a cluster of tiny hollow air sacs - alveoli - where gas exchange takes place
The human lungs contain approximately 300 million alveoli!
Each alveolus is surrounded by a network of capillaries
The walls of the alveoli and capillaries are each only one cell thick
Intercostal muscles
muscles between ribs
what part of the brain controls breathing?
medulla oblongata
Chemoreceptors
Chemoreceptors in the medulla oblongata detect CO2 levels in the blood
sense low pH and relay message to stimulate the diaphragm and intercostal muscles
When CO2 levels decrease, and blood pH is returned to normal, the chemoreceptors are inactivated
Tidal volume
the amount of air that passes in and out of the lungs with each breath
Total lung capacity
the maximum volume of air that can be held in the lungs
expiratory reserve volume
After the normal tidal volume is exhaled, more air can be forcefully exhaled
inspiratory reserve volume
During a deep breath, an extra volume of air can be inhaled
Vital Capacity
The maximum amount of air that can be moved into and out of the respiratory system is called the vital capacity; this value is always 1-1.5L LESS than the total lung capacity… WHY?
If the lungs became completely deflated, they would collapse
The 1-1.5L of air that always remains in the lungs is called the residual volume
Four Main Functions of the circulatory system
Transportation of oxygen and carbon dioxide
Distribution of nutrients and wastes
Maintenance of body temperature
Circulation of hormones
Structural Components of Circulatory System:
A fluid in which material is transported
Blood
A system of blood vessels or spaces through which the fluid moves
Veins, arteries, capillaries
A pump that pushes the fluid through the vessels or space
Heart
Components of Blood
Blood is made in the bone marrow and stored in the spleen.
An average person has about 5L of blood circulating through his/her body
55% is made up of plasma liquid (water, proteins, solutes)
45% is made up of the following:
red blood cells (erythrocytes)
white blood cells (leukocytes)
Platelets (thrombocytes)
Plasma
A fluid medium in which solid blood components are transported
Contains a number of dissolved proteins and nutrients
Albumins
Determines how much water enters/leaves bloodstream
Globulins
Transport lipids, cholesterol, fat soluble minerals
Immunoglobulins helps fight diseases
Fibrinogens
Helps with blood clotting
