Week 7 Flashcards
heterotrophs
get energy and chemical building blocks from eating other organisms
Calorie
amount of heat needed to raise 1 gram of water 1 degree
Metabolic rate
amount of energy an animal converts to heat per day
What most energy is stored as
lipids as they store the most energy with little water
Essential nutrients
required but cannot be synthesised
Standard amino acids
20 amino acids that animals need to build proteins, animals can synthesise some of the nonessential amino acids
Essential amino acids
ones that cant be synthesised and must come from food
Vitamins
essential nutrients
carbon compounds, needed in tiny amounts
either water or lipid soluble
some animals can synthesise some vitamins
Minerals
some are required in large amounts while others are needed in small amounts
Nutrient deficiency
malnutrition
Aquatic suspension feeders
collect tiny organic particles
have evolved mechanisms for filtering
Symbiosis
intimate long term association with microbes that synthesise important nutrients for animals
ruminant mammals
cow, sheep - have evolved complex stomachs of four chambers
Rumen
complex microbial community of bacteria that break down the chewed food by fermentation
microbes - produce
produce some vitamin b and essential amino acids that recycle nitrogen which is used to build proteins
Digestion
breakdown of large food molecules by enzymes in gut lumen to produce smaller molecules
Absorption
transport of small molecules for gut lumen into the blood
Mucosa
gut epithelium and underlying connetive tissue
Submucosa
blood and lymph vessels that carry absorbed nutrients to the rest of the body plus neurons that control secretory functions
Layers of smooth muscle around the submucosa
circular
longitudal
circular smooth muscle
innermost cells oriented around the gut that constrict the gut
longitudinal muscle
outermost cells oriented along the gut that shorten the gut
sphincter muscles
control food movement by encircling the gut and contracting tightly to seal off one part of the gut from another
Digestive enzymes
break bonds by hydrolysis
classed according to the type of molecules they digest and where they act
Lipase
hydrolyses fat
Protease
hydrolyses proteins
Carbohydrase
hydrolyses bonds between sugar in carbs
Intraluminal enzymes
digest food molecules in the lumen
Membrane associated enzymes
attached to epithelial cells lining the gut lumen
Intracellular enzymes
inside some gut epithelial cells
Fore gut
mouth, esophagus and stomach
Stomach Function
stores food
secretes HCL
begins protein digestion by pepsins
squeezes and mixes food with acid and enzymes
pepsins
enzymes secreted by epithelium
digest proteins
Midgut
smaller diameter intestine, activates enzymes
Hinder Gut
larger diameter intestine
stores indigestable wastes and completes reabsorption of water and salts
Pancreas
secretes digestive enzymes along with bicarbonate ions that neutralise tha acid, that flows into midgut via duct
Lipid digestion
liver secretes bile that emulsify lipids, increasing surface area for digestive enzymes
broken down into fatty acids and glycerol
Absorptive state
after meal when food is in the gut and nutrients are absorbed
Post absorptive state
stomach and small intestine are empty and metabolism runs on stored nutrients
hormones regulate
appetite
digestion processes
Gastrin
is stimulated when food arrives in gut
stimulates release of HCL and pepsin
Secretin and cholecystokinin
triggered by entry of food in midgut
inhibits stomach acid secretion and muscle contraction until food is processed
Secretin and cholecystokinin stimulate
pancreas to secrete digestive enzymes and bicarbonate
liver to secrete bile
Ghrelin
secreted when stomach is empty, stimulates appetite
Leptin
provides feedback to brain about body fat
insulin
secreted by pancreas
stabilises blood glucose levels and promotes storage of glucose by stimulating liver to make glycogen
Glucagon
promotes glycogen breakdown into glucose and breakdown of stored lipids and release fatty acids
gas exchange
the uptake of oxygen and the discharge of CO2
gastrovascular cavities
animals with simple body plans
body wall only a few cells thick encloses central gastrovascular cavity
fluid inside cavity is contigous with water outside
oxygen can diffuse directly in
multilayered organisms - gastrovascular cavities
dont work as diffusion distance is too great
open circulation
blood bathes in organs directly
closed circulation
blood confined to vessels and distinct from interstital fluid
materials are exchanged by diffusion between the blood and interstital fluid
Fish circulatory system
simple closed system
2 chambered heart and single circuit of blood
Amphibian circulatory
3 chambered heart and 2 circuit blood flow
pulmocutaneous and systemic
pulmocutaneous
through lungs and skin
systemic
through body
Reptile circulatory system
3 chambered heart
single ventricle is separated by septum
Mammals and birds circulatory system
4 chambered heart
complete separation between blood
complete double circulation
Heart Rate
number of beats per minute
mammal circulation
blood flows with right ventricle pumping blood to lungs
lungs oxygenates blood
oxygenated blood from lungs enters the heart at the left atrium and is pumped through aorta to body tissues by left ventricle
blood returns to heart through superior and inferior vena cava which flows into right atrium
atrioventricular valves
prevent back flow of blood
separate each atrium and ventricle
Semilunar valves
controls blood flow to the aorta and pulmonary artery
blood
specialised connective tissue
consists of several cells suspended in plasma
Erythrocytes
red blood cells
transport oxygen and CO2
contain haemoglobin
Leukocytes
white blood cells
defense and immunity
eat bacteria and debris
produces antibodies
Platelets
blood clotting
Plasma
90% water
contains inorganic salts and plasma proteins
Plasma proteins
influence blood pH, osmotic pressure, viscosity, lipid transport, immunity and blood clotting
