biology
Biology
- 2 major ways that molecules can be moved across a cell membrane
- The distinction has to do with whether or not cell energy is used
- Passive transport (no energy needed)
- Active transport (energy needed)
- Passive transport molecules travel down the concentration gradient from high to low
- Active transport travel against the concentration gradient from low to high
- 2 different types of diffusion
- Higher concentration of molecules outside the cell than inside the cell
- Diffusion molecules travel across the membrane
- Simple diffusion molecules travel down their concentration gradient through the membrane but these molecules need to be small and nonpolar
- facilitated diffusion go through a channel protein
- Osmosis is the movement of water from a less concentrated solution to a more concentrated solution through a semi-permeable membrane
- The important thing to remember is that osmosis is the movement of water not the particles dissolved in the water
- For example if you split a beaker of water into two halves with a semi-permeable membrane in the middle and added salt to one the water would move from the side of the beaker with no salt until both concentrations are the same
- Facilitated diffusion is diffusion that is helped along by a membrane
- The difference in the concentration of a substance between two areas is called the concentration gradient the bigger the different the steeper the concentration gradient
- Passive transport is a automatic movement
- Active transport is not a automatic movement and needs energy to move through and against the concentration gradient
\ \ \ \ \ \ \ \ \ \ \ \ \ TERM 3
A- Adenine
T- Thymine
C- Cytosine
G- Guanine
Adenine pairs with thymine, and cytosine pairs with guanine.
2 main processes- translation and transcription
Muscle cells are joined together to form a tissue and are a part of an organ.
Multicellular organisms have a hierarchical structure of organizations of cells, tissues,
Stems cells- muscles cells, fat cells, bone cells, blood cells. Sex cells, skin cells
Four basic types of tissues
Epithelial are responsible for protecting surfaces
connective tissue support and bind
Muscle are able to contract
Nervous tissue can detect stimuli and transmit messages.
Parts of the heart
Vena cava
Brings deoxygenated blood from the body to the heart (right atrium)
pulmonary artery
Deoxygenated blood from the heart ( right ventricle) to the lungs
pulmonary vein
Oxygenated blood from the lungs to the heart ( left atrium)
Aorta
Oxygenated blood from the heart ( left ventricle) to the body
cycle of blood
Body cells > vena cava > right atrium > right ventricle > pulmonary artery > lungs > pulmonary vein > left atrium > left ventricle > aorta > body cells
3 blood vessels
arteries, veins, capillaries
function of arteries
carry blood away from the heart at high pressure
structure of arteries
Thick muscular walls to withstand pressure
function of veins
carry blood to the heart at low pressure
structure of veins
Thin muscular wall with valves
purpose of valves
prevent backflow
function of capillaries?
Efficient exchange of gasses
structure of capillaries
narrow vessels with thin walls, forming networks at tissues, large surface area
What does blood transport?
Oxygen, nutrients, carbon dioxide
What does the blood contain ?
plasma, red blood cells, white blood cells, platelets
What is the function of red blood cells?
Transport oxygen, specialized with biconcave shape and no nucleus, contain hemoglobin
function of white blood cells?
fight off pathogens
What are the two cells involved with white blood cells?
Phagocytes- carry out phagocytosis by engulfing pathogens
Lymphocytes- produces antibodies which destroy pathogens
What is the function in hemoglobin?
Contains iron and binds with oxygen to form oxyhemoglobin
What are the key structures of the villus?
Thin cell layer - allows for quick diffusion
Blood capillary - transports glucose and amino acids
Lacteal - transports fatty acids and glycerol
What are the key structures of the lungs?
Trachea, bronchus, bronchiole, alveoli , capillary
What are the structures of the trachea?
Rings of cartilage
Mucus
Cilia
What are the functions of each structure in the trachea?
Rings of cartilage- keeps airways open
Mucus - traps dirt and microorganisms
Cilia - tiny hair like structures, moves mucus up and away from the lungs
What is the pathway of air into the lungs?
Trachea > bronchus > bronchiole > alveoli > capillary
What are some features that increase efficiency around the lungs?
Large surface area - many air sacs
One cell thick - quick diffusion
Moist lining - allows oxygen to dissolve and diffuse quicker
Extensive blood supply/many blood capillaries - rapid transport of oxygen
What changes happen to your breathing muscles, rib cage, lung volume and pressure when you inhale?
Breathing muscles = contract
Rib cage = up and out
Volume = increases
Pressure = decreases
What happens to your breathing muscles, rib cage, lung volume and pressure when you exhale?
Breathing muscles = relax
Rib cage = down and in
Volume =. Decreases
Pressure = increases
Digestive System
Four main process
Ingestion - taking food into our body
Digestion- chemical or mechanical
absorption - small molecule products enter the bloodstream
egestion - leaving the body
Food is a mixture of many substances
Macromolecules
Carbohydrates
Proteins
lipids
Lipid broken down by lipase
Carbohydrates broken down by amylases
Protein broken down by proteases
\ Excretion
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Animals excrete things that include carbon dioxide and nitrogen
Feces are not considered a waste because they are produced by a metabolic reaction mostly undigested food
Respiratory system responsible for getting rid of carbon dioxide
Skin is responsible for removing water, salts, urea
Vena cava
Aorta
Renal vein
Renal artery
Kidney
Ureter
Bladder
Urethra
Blood passes through the kidneys and is filtered and the blood that comes out of that oxygenated comes through the renal vein and is deoxygenated.
Kidney
Produces urine to remove nitrogen - containing waste
Ureter
Transports urine from the kidneys to the bladder
Bladder
Stores urine
Urethra
Transports urine out of the bladder during urination
Each day the kidney filters about 180L of plasma
And most is reabsorbed
MEANING about 1L of urine output
Kidney tissue consists of 3 distinct regions
Medulla (inner region)
Coretex (outer region)
Pelvis (top of ureter)
The kidneys help to maintain the body's internal chemical balance by adjusting the composition of the fluid excreted
Nephrons are the structure that permits nitrogen containing waste to be removed by the kidney
Blood flows in through the renal artery and into the glomerulus it's a sack of capillaries
Capillaries are one cell thick. Surface area
Plasma comes out of the glomerulus and goes through the nephron
Blood plasma leaves the glomerulus and enters the bowmans capsule
High pressure
Pores in the capillaries
Waste filtered out of the glomerulus is called glomerular filtrate
Contains
Water
Urea
Glucose
Ions
Reabsorption
Substances the body still requires are reabsorbed back into the nephron
This includes
Glucose
Most water
Sodiums ions
Amino acids
Glomerulus
A cluster of capillaries with tiny pores in their walls
The cowmans capsules
Cupe shaped and hollow
Proximal tubule
Tube like
\ \ \ Plants
Epidermis
Found near root tips
Xylem
Inside stem is made up of tube like cells called xylem vessels
Mesophyll
In the leaves made up of spongy mesophyll cells
Reproductive
In a flower- cells in ovary produce ova
Near root tips epidermis is one cell thick layer of tissue that include hair cells that have an extension to maximize uptake of water and minerals from soil
Chains of xylem vessels structure of xylem in the stem allows the transport of water and dissolved minerals from the roots to the other parts of the plant
The function of the leaf is to carry out photosynthesis
It is able to take place in leaves because mesophyll tissue contains cells with many chloroplasts
Monocot
Seed
One cotyledon
Root
Fibrous roots
Vascular
Scattered
Stomata lets in carbon dioxide
Closed at night due to no sun, open during the day
Osmosis
Diffusion of water across a cell membrane high - low
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