exam 2 Flashcards
digestive system
- the process when large complex molecules are broken down into simple substances
- animals make energy using food and oxygen
herbivore and omnivore digestive system
- long digestive system
- harder to digest cellulose
- bacteria in the intestines to help
carnivore digestive system
- short digestive system
- protein easier to digest then cellulose
mechanical digestion
- when large pieces of food are broken down into smaller parts through chewing or muscular movement in the stomach
- aim is to increase surface area of food so i can be acted on by enzymes in chemical digestion
chemical digestion
- when enzymes break down complex substances into their simplest form
e. g. carbs - glucose
roles of the digestive system
ingestion
digestion
absorption
egestion
ingestion
- taking in of nutrients into the mouth
adaptations - organism choosing suitable food for ingestion
- physical features such as catching food
digestion
- chemical and mechanical breakdown of food into small molecules that can be absorbed
adaptations - structure / number of teeth
- foods the animal can digest
absorption
the taking up of digested moeluces into the internal environment of the cells digestive tract
digestion
the removal of waste from the body
transport system of the body 4 main functions CS
- transportation of water, oxygen and carbon dioxide
- distribution of nutrients and removal of waste
- maintenance of body temp
- circulation of hormones
naming system extended response
- first step is to place an organism into its kingdom based on cell structure / distinguishing features
- organisms that are more closely related will have more characteristics in common then others
- organisms are then divided into next hierarchical divisions (phylum, class, order, family, genus, species
- organisms are categorized into divisions based on shared characteristics and methods of reproduction
- modern technology has allowed relationships to be established by comparing DNA and molecular sequences, helped to classify species and reclassify organisms into more appropriate divisions
- each member of a species is assigned a unique and defining 2 part name
- binomial name represents the genus and species of the organisms. species is italicized
- important because it allows scientists to accurately identify individual species without any confusion
- classification is used to analyse information about organisms and their relationship with other organisms
- important for communication and collaboration amongst scientist around the world
what is biodiversity, what are major threats and what are some possible solutions
- biodiversity refers to the variation of genes, species and ecosystems that exist
threats:
loss of habitat eg land clearing/ wetland drainage
due to housing/ farming
pollution
climate change
introduction of species
solutions:
creation of national parks and conservation zones
reducing hunting seasons and size restrictions
revegetation
public awareness campaigns
global agreements
compare abiotic and biotic features of rainforest and desert ecosystems
desert abiotic: high temp high light wide temp variations low water soil infertility biotic: small biomass reptiles xerophyte plants low biodiversity rainforest biotic : high humidity high rainfall high temp high to low light levels biotic: large biomass large trees mammals amphibians high biodiversity
circulatory systems of bird and an insect
bird: closed circulatory system have vessels double circulatory system 4 chambered heart materials transported in blood insect: open circulatory system flows through body cavity materials transported in haemolymph
passive processes by which materials move across a membrane
cell membrane is made of phospholipid bilayer and proteins that is semi permeable
diffusion:
passive = does not use energy
moves materials across membrane from high concentration to low concentration
facilitated diffusion:
movement from high to low concentration across a carrier protein
osmosis:
passive
movement of water form low lute concentration to region of high solute concentration
anaerobic vc aerobic respiration
anaerobic: occurs in cytoplasm partial breakdown of glucose to produce lactic acid small amount of energy released aerobic: uses O2 occurs in mitochondria complete breakdown of glucose to produce carbon dioxide and water large amount of energy released
positive and negative impacts of low intensity fires
positive:
nutrient recycling = releases carbon that is locked up in the carbon cycle providing nutrients to establishing species
stimulates germination of some species, compounds in smoke stimulate seeds to germinate, heat of fire breaks open hard fruit seeds to germinate
more light goes to the forest floor after fire as branches from upper story are removed allowing understory species to grow and increase in density
stimulates flowering
negative:
increase space for weeds to colonies
fire sensitive species may reduce in number over time therefore reducing diversity of ecosystem
some species requiring high intensity heat to germinate may decrease in low intensity fire
regular burning could change the canopy structure of the forest
fluid mosaic model
phospholipid bilayer, hydrophilic heads and hydrophobic tails
proteins imbedded in membrane, carrier and channels
glycoproteins - stability, cell recognition
cholesterol - membrane consistency
gylcolipid - attached to phosphate head, cell signaling and recognition
protein channels and carriers allows passage of large molecules such as amino acids
osmosis allows movement of water from low to high solute concentration
passive diffusion of molecules across the membrane occurs without energy, small molecules eg oxygen and co2
active transports when a molecule is needed in greater concentrations
action of enzymes with reference to lock and key model and induced fit model, identify the factors that can limit their function
enzymes are biological catalysts that speed up reactions
catabolic and anabolic
without enzymes chemical reactions in our bodies would not occur quickly enough
lock and key model:
substrate fits perfectly into the active site of the enzyme where the reaction takes place
each substrate has a specific enzyme with a specific active site
induced fit model:
substrate enters the active site of an enzyme
enzyme changes shape to cost around substrate
both are reused in other reactions
enzyme function is carried out under specific conditions
enzyme function will reduce or stop if the conditions in which they function move out of the optimum range
factors eg pH, temp, substrate concentration, enzyme concentration, coenzymes, inhibitors
temp can cause the enzymes to denature
increase in concentration of enzymes substrates and coenzymes can increase rates of reaction
