Exam Revision Sem 1 Flashcards
Function of mitochondria
Double membrane
Cellular respiration
Makes energy available for the cells activities
Function of Golgi apparatus?
Modifies proteins and packages them for secretion from the cell
Centrioles:
Involved in the reproduction of the cell
Endoplasmic reticulum:
Provides a surface for chemical reactions
Lysosomes:
Contain digestive enzymes
When particles/liquids enter the cell they form vesicles in cytoplasm, lysosomes join these vesicles and break down material
Nucleus:
Membrane separates from cytoplasm, stores energy and genetic information (DNA)
Why are cells so small?
All the requirements of a cell and the organelles must pass across the membrane
Inclusions?
Chemical substances occurring as granules or liquid droplets in the cytoplasm
Structure of the cell membrane?
Semipermeable
Separates cell from neighbouring cell
Separates intercellular fluid and extracellular fluid
Gives the cell structure
Passive process?
Requires no energy, moves with the concentration gradient examples include diffusion, osmosis
Active processes?
Require energy, move against the concentration gradient
Examples are active transport, vesicular transport
What is osmosis?
Diffusion of water, requires channel proteins
Movement of water from a region of high water concentration to a region of low water concentration
What is carrier-mediated transport?
When large molecules are too big to pass through channels, they attach to a binding site on the carrier (proteins are specific)
What is vesicular transport?
Movement of substances in vesicles across the membrane.
What is exocytosis?
Removing a liquid/solid out of the cell
Vesicle formed inside the cell via the Golgi apparatus
Vesicle then fuses with cell membrane and contents are pushed outside into extracellular fluid.
What is endocytosis?
Taking liquids/solids into a cell
Cell membrane folds around the particle and encloses, forming a vesicle
Vesicle then suspended in the cytoplasm
Pinnocytosis?
Movement of liquid into cell
Phagocytosis?
Movement of solids into a cell
What is homeostasis?
Where the body systems work together to make sure the cellular environment stays constant. (Temperature and fluid concentration)
What is facilitated diffusion?
A passive process where particles move from an area of high concentration to low concentration, require no energy and move against the concentration gradient
Three types of osmotic solutions?
Isotonic
Hypotonic
Hypertonic
Isotonic:
There is the same concentration of solute molecules inside and outside the cell
Hypotonic:
Solute outside the cell is low concentration (10%) inside the cell higher solute conc (90%)
When water moves into the cell osmotic pressure increases
Hypertonic:
Greater concentration of solute molecules outside the cell rather than inside
Water moves outside the cell causing it to shrink.
Epithelial tissue:
Covering or lining tissue, found in the heart, kidneys, intestines, liver (outside lining) as well as lining the inner layer of the heart, stomach and other hollow organs.
Connective tissue:
Provides support for the body, cells are not close together like they are in epithelial tissue> separated by non-cellular material called the matrix eg cartilage, ligaments, tendons and bone
Muscular tissues:
Skeletal muscle: muscles attached to the bones (voluntary movements)
Involuntary muscle: cells we cannot voluntarily contract > in the stomach walls, intestines, iris ams uterus
Cardiac muscle: heart muscle , makes up most of the heart , not voluntary
Nervous tissue:
Made up of specialised nerve cells (neurons) found in the brain, spinal cord and nerves.
Catabolism:
When large cell molecules are broken down into smaller molecules and release energy.
Anabolism:
When small molecules are built up into larger molecules, require energy.
Organic compounds:
Large molecules that contain carbon ie, carbohydrates, amino acids, proteins, lipids and nuclei acids
Enzymes:
Proteins that allow for chemical reactions (breaking down and building up of substances) to take place at body temperature.
Are biological catalysts
Five factors affecting enzyme activity:
- Concentration of enzyme
- Concentration of substrate
- temperature (optimum temp is 37°)
- PH level
- co-factors (can denature activation site shape so the enzyme can bind with the substrate)
Cellular respiration:
When organic molecules (food) is broken down to release energy.
- carbs > glucose
- proteins > amino acids
- lipids > fatty acids and glycerol
Cellular respiration formula:
Glucose + oxygen –> carbon dioxide + water + ATP
What occurs in cellular resp?
60% of available energy is released as heat
40% used to from adenosine triphosphate (ATP)
Inorganic phosphate group joins in to from adenosine diphosphate (ADP)
The bond between ADP and the 3rd phosphate is easily broke
Anaerobic respiration:
Occurs without oxygen Allows cells to reproduce energy Glycolysis --> 2 molecule sof pyurvic acid Occurs in cytoplasm Incomplete glucose break down Forms 2 ATP
Aerobic respiration:
Require oxygen Complete breakdown of glucose Occur sin mitochondria Products are water + CO2 Produces 34 ATP form electron transport, 2 ATP from krebbs cycle
What do cells use energy for? (7)
- building complex molecules
- cell division and growth
- movement of cell organelles
- movement of whole cell
- maintaining cell organisation
- active transport
- transmission of nerve impulses
What is synthesis?
Combining of small molecules to make larger molecules
Circulatory system functions: (5)
Transports oxygen Removal of carbon dioxide Transport of nutrients Maintains body temperature Regulates PH levels in the blood
What are the 4 components of blood?
Erythrocytes- RBC
Leucocytes- WBC
Thrombocytes- platelets
Plasma
Function of erythrocytes?
Combine w oxygen and form oxyhemoglobin, produced in bone marrow, destroyed in spleen + liver
Function of leucocytes?
Remove dead cells and invading microorganisms, live from minutes to years
Function of Thrombocytes
Formed in red bone marrow, sticky, necessary for blood clotting (last 7 days).
The Heart:
Double pump
- As blood is pumped through the capillaries it loses most of its pressure
- after going through lungs, blood pressure is so low it needs to be pumped through the heart before travelling to the body
- the right side pumps blood to the lungs
- the left side pumps blood to the rest of the body
Blood vessels:
Arteries (away from heart)
Capillaries (between cells)
Veins (towards the heart)
4 stages of blood clotting:
- Arteries construct to reduce blood flow
- Platelets stick to rough surfaces and attract more platelets, acting as a plug
- Platelets release vasoconstrictors
- Plug and constriction is enough to stop bleeding.
Coagulation :
(Major damage)
- clotting factors present in plasma form protein threads called fibrin
- fibrin forms a mesh to trap blood cells, platelets and plasma
- mesh threads contract and become denser and stronger, pulling blood vessel edges together (clot retraction)
- serum is squeezed out and the clot dries forming a scab.
What is the lymphatic system?
- As blood enters the capillaries, the high pressure forces some of the fluid in the blood through the capillary walls into the tissues
- main function is to collect the escaping fluid and return it to the circulatory system
Lymph vessel:
Originate as blind-ended tubes in the spaces between the cells of most tissues
- more permeable
- network of lymph vessels join up to form 2 lymphatic ducts that empty lymph into large veins in the upper chest
Lymph nodes:
Occur at intervals along the lymphatic vessels
Each surrounded by a capsule of connective tissue that extends into the node forming framework
The lymph passes through several nodes before entering the circulatory system.
Outside the lungs:
- membrane called the pleura covers the surface of the lungs
- between 2 layers of membrane is the pleural fluid (holds the lungs against the inside of the chest wall and allows the lungs to slide when breathing.
Inside the lungs:
Bronchi branch ends in bronchioles
The smallest bronchioles open into clusters of tiny air sacs called alveoli
Alveoli are the exchange surface for respiratory gases
Each alveolus is surrounded by a network of blood capillaries.
The mechanics of breathing- inhaling (3 steps)
- Intercostal muscles contract to move ribcage up and outwards
- Lung volume increases, diaphragm contracts and moves down
- Air flows from high pressure external environment to area of low pressure into lungs
The mechanics of breathing- exhaling (3 steps)
- intercostal muscles relax to move the ribcage down and inwards
- lung volume decreases, diaphragm relaxes and moves upwards
- Air flows from high pressure in lungs to low pressure external environment.
Systole:
Pumping phase where the heart contracts
Diastole:
The filling phase of the heart
How are lungs well suited to gas exchange?
Large surface area
Rich supply of blood vessels
Thin membrane
Lungs positioned deep inside the body (to prevent excess fluid evaporation)
Lung volume can change by movement of respiratory muscles so that air can flow in n out of lungs
Processes in gas exchange?
- arteries bring deoxygenated blood, high in CO2 to the lungs
- CO2 moves from high to low concentration and diffuses across membrane into alveolus
- oxygen moves from high to low concentration and diffuses across membrane into blood
- veins carry oxygenated blood, low in CO2 form the lungs
How is the concentration gradient maintained?
Constant flow of blood
Movement of air in n out of lungs
What are the 7 nutrient groups?
Carbohydrates Proteins Lipids Water Minerals Vitamins Fibre
Digestion in the mouth:
Mastication occurs (chewing of the food) Salivary glands secrete salivary amylase
4 types of teeth:
Incisors- biting and cutting food
Canine- tearing
Premolars and molars- crushing and grinding food
Digestion in the Oesophagus:
Movement of food down the tube (peristalsis)
Oesophagus secretes mucus to lubricate the bolus
Digestion in the stomach
3 types of muscle- longitudinal, oblique and circular, contract, churn and mix the food with the gastric juices
Enzyme : pepsin
Substrate: protein
Product: polypeptide
Digestion in the small intestine/ ileum:
Wave-like muscle contractions move the chyme along the tubing (segmentation) pancreatic and intestinal juices with enzymes are secreted
Liver:
Produces bile, duodenum breaks down bile in a process called emulsification.
Gall bladder:
Stores bile–> releases to small intestine, bile emulsifies liquids
Pyloric sphincter:
Band of circular muscle that regulates material flow from stomach to duodenum.
Pancreatic lipase:
Substrate: lipids, tri-glyceride
Products: fatty acid + glycerol
Pancreatic protease:
Substrate: protein and polypeptides
Products: peptides
Pancreatic amylase:
Substrate: starch
Product: dissachoride
Intestinal lipase:
Substrate: lipids, triglyceride
Product: fatty acid and glycerol
Intestinal amylase:
Substrate: disaccharide
Enzyme: monsaccharide (glucose)
Pancreatic protease:
Substrate: peptide
Product: amino acid
The 5 functions of the skeletal system:
Framework Movement Production Storage Protection
Yellow bone marrow:
Storage of fat
Compact bone:
Non porous, stores salts, strong, give support
Periosteum:
Fibrous connective, covers the whole bone
Red bone marrow sponge:
Cancellous bone, porous, production of RBC and WBC and platelets
Articulate cartilage:
Smooth movement, made of collagen
Absorption in the small intestine:
90% occurs in the small intestine
Absorbed by circular folds covered in tiny hair like features called villi, covered in microvilli. Connected to a network of blood capillaries allowing for a large surface area.
Formula for cardiac output (ml/minute):
Stroke volume (mL) x heart rate (bpm)
What is cardiac output?
The amount of blood leaving one of the ventricles every minute
How to test for macro nutrients in different foods using chemicals ?
Iodine tests for starch
Benedict tests for glucose
Biuret tests for protein
Grease spot tests for fat
Characteristics Fibrous joints:
No movement between the bones
Bones held in place by fibrous connective tissue
Very difficult to damage
Eg sultures of the skull
Cartilaginous /slightly moveable joints characteristics:
Held in place by cartilage
Eg the junction of the two pelvic homes (the public symphysis), joints between adjacent vertebrae, joints between ribs + sternum
Synovial/freely moveable joints:
Movement is limited by ligaments, muscles, tendons and adjoining bones
Eg shoulder, elbow,wrist,fingers,knee, hip
Ball and socket joints:
Spherical head fits into a cup-like cavity
Eg scapula + humerus, femur + pelvis
Hinge joints:
Allow movement in one plane only, form when the convex surface fits with concave surface
Eg elbow, knee
Pivot joints
Rounded, pointed end of bone articulates with a ring (formed of bone +ligament)
Eg first vertebrae (atlas) and the second vertebrae (axis)
Gliding joints
Movement in any direction (side to side, back and forth)
Eg carpal and tarsal bones, the sternum and clavicle
Saddle joints
Only occurs where the thumb connects to the palm and convex in the other
Condyloid joints:
Slightly convex surface into slightly concave depression
Eg the radius + carpal bones, metacarpal + phalanges
3 muscle properties:
Contract
Extensibility
Elasticity
3 types of muscle :
Smooth (involuntary)
Cardiac
Skeletal
Skeletal muscle properties:
Elongated, Mostly attached to bones Allow movement at the joints Mostly voluntary Gove body shape
Smooth muscle properties:
Spindle shaped with single nucleus
Occur in the muscles of internal organs
Involuntary
Functions of the muscle:
Move bones by contracting Stabilise body positions Regulate organ volumes Movement of substances within the body Create heat
Actin and myosin:
Proteins that enable cells to shorten
Because the muscles are anchored
