Bio sac

Chapter 5A - Cells to System

Cells → Tissue → Organs → Organ System

Organisation of Plants

Plants: Cells

• Parenchyma - Photosynthesis

• Sclerenchyma - Providing support to plants

• Collenchyma - Providing support to plants

• Xylem - Responsible for transport of water from roots to leaves

• Phloem - Responsible for transport of food & nutrients

Tissues : Plant tissues

• Ground tissue - Tissues inside the plant

• Dermal tissue - Coating over the leaves

Organs:

• Stem

• Leaves

• Flowers

• Fruits

• Root

Organ System:

• Root system - Below ground level

• Shoot system - Above ground level

Organisation of Animals

Cells - Skin, brain, liver, muscle, blood, nerve, fats

Chapter 5B - Plant Vascular Tissues

Plant Vascular tissues:

• Xylem (Transport of water) → Roots absorb water from soil (diffusion, extracellular pathway, cytoplasmic pathway)

• Phloem (Transport of sugar & other nutrients from leaves to other parts of body)

Source (leaves) → Companion cells → Sieve cells

                                                                             1. Conc of food in sieve cells

                                                                             2. Water diffusion → Xylem

                                                                             3. After transporting food to other parts of plants → water                          will diffuse into xylem  

Transpiration & Translocation

Transpiration → Movement of water up by xylem and its exit vis stomata

1. Assist in photosynthesis process

2. Regulates heat

3. Distribution of nutrients across different parts of plant

4. Prevents witting of leaves

Factors that affect transpiration

1. Temperature

2. Light

3. Humidity

4. Wind

5. Water availability

Translocation → Movement of food through phloem

Cohesion → Sticking of water molecules with each other

Adhesion → Sticking of water molecules on xylem

Chapter 5C - Digestive System

Mechanical - Breaking down food into smaller pieces

Food: Macromolecules, Micromolecules

Macromolecules

1. Carbohydrates

2. Proteins

3. Fats

Micromolecules

1. Vitamins

2. Minerals

3. Dietary fibres

Digestion: Physical, Chemical

Physical (Mechanical)

Chemical (Enzymes)

1. Amylase - Carbs

2. Protease - Proteins

3. Lipase - Fats/Lipids

Steps involved in digestion

1. Ingestion

2. Digestion

3. Absorption

4. Egestion / Elimination

Anatomy

• Mouth → Mechanically digest food by mastication (chewing) it into smaller pieces

• salivary glands → provides water to make food moist and mucus which makes it slippery, saliva also has amylase which is a enzyme that digest starch

• oesophagus → Surrounded by smooth muscle that squeezes the food, this process is called peristalsis

• stomach → Mixes food with pepsin which is a enzyme that begins chemical digestion

• small intestine → Most important organ it contributes to the chemical digestion of food and absorption, they also produce amylase, protease, lipase and mucus

• large intestine

• liver

• gall bladder

• pancreas → It contains bicarbonate ions neutralises the pH of food leaving the stomach

Chapter 5D - Excretory system

To remove excess and unwanted substances from body such a CO2, toxins and nitrogenous waste products.

Organs - Lungs, Skin, Kidneys, Liver, Bladder

Proteins → Amino Acids → Small intestine absorbs → Liver → Amino acids → Ammonia (toxic) → Kidneys → Urea → Urine

The nephron filters and and reabsorb needed materials, and produces urine with the undeeded materials

Chapter 5E - The Endocrine system

1. Endocrine glands are glands that produce hormones (signalling molecules)

2. Hormones are very specific

1. Endocrine system is made up of so many glands - such as hypothalamus ( brain), pineal gland (brain), pituitary gland (brain), thyroid gland (neck), thymus (is in between lungs), pancreas (in abdomen behind stomach), adrenal gland (at the top of kidneys), placenta (present only during pregnancy & maintains healthy pregnancy), ovaries (maintain reproductive system)

Steps of hormone secretion and reception

1. An endocrine cell produces and secretes a hormone.

2. The hormone travels from the endocrine cell into the bloodstream.

3. The hormone leaves the bloodstream and arrives at a target cell.

4. The hormone binds to a receptor on the target cell.

5. The target cell undergoes a response.

Chapter 6A - Homeostasis

• Maintaining internal environment of an organism with set limits so that cell and body systems can work properly irrespective of changes in external environment.

1. Stimulus response model → Stimulus → Receptors → Modulator → Effector → Response

• Receptors ( Thermoreceptor - Detects change in temperature) ( Baroreceptors - Detects change in pressure) (Nociceptors - Detects change in painful stimuli) (Chemoreceptors - Detects change in chemicals) ( Photorecptors - Detects change in light)

1. Feedback loop (Positive/negative feedback)

Receptors (Detects stimulus) → Effector (response)

Chapter 6B - Regulation of body temperature

Conduction - Heat transfer through physical contact

Convection - Transfer of heat via movement of liquid or gas

Evaporation - Heat transfer due to conversion of liquid to gas

Radiation - Transfer of heat through electro magnetic waves

Species:

• Endothermic ( warm blooded animals) are able to generate the majority of their heat energy internally using metabolic processes.

• Exothermic ( cold blooded animals) produce very little metabolic energy, and instead rely on environmental sources of heat to warm themselves.

Hypothermia is when when the body temperature is too cold

Hyperthermia is when the body temperature is too hot

• How body regulates temperature

Chapter 6C - Regulation of blood glucose

glycogen - a polysaccharide of glucose that stores energy. Serves as the main storage of glucose in the body

glycogenesis - the process of creating glycogen from glucose

glycogenolysis - the process of breaking down glycogen into glucose

1. Glucose is the main source of energy

Food → Carbohydrate → Digestive system → Breaks down carbohydrates into monosaccharides (glucose) → Small intestine → Blood → Cells → To function

Blood glucose level 4-7.8 mmol/L

<4 hypoglycaemia (Lower level of glucose in blood)

7.8 hyperglycaemia (more levels of glucose in blood)

Change in blood glucose → pancreas (Islet of langerhans)

1. Alpha (Low blood glucose)

2. Beta (High blood glucose)

Beta → Secretes insulin

1. Stimulate liver → Convert extra glucose into glycogen

2. Skeletal cells

Alpha → Secrete glucagon → glycogen → glucose (gylcogenesis)

Glucagon falls under alpha and insulin is under beta cells of islets of langerhans of pancreas

If glucose levels are too high increased insulin production will start by the pancreas, If the glucose levels are low they will produce glucagon.

Chapter 6D - Regulation of water balance

hypotonic - describes a solution with a lower solute concentration when compared to another solution

hypertonic - describes a solution with a higher solute concentration when compared to another solution

isotonic - describes a solution with an equal solute concentration when compared to another solution

The body should be isotonic

1. Osmoregulation (osmosis) is the process by which water is regulated in the human body.

2. Average human body has 55-66% of water.

3. Water is inside the cell (intracellular) and outside the cell (extracellular)

Functions of water

• To maintain blood pressure & volume

• Urine production

• Removal of waste products

• Productions of cerebospinal fluid (CSF) which surrounds your brain and spinal cord

Change in H2O volume Either too much or less water

1. baroreceptors → Works on cells in kidneys → Distal convolulated tubules & collecting ducts will work accordingly → Alter water reabsorption

2. Osmoreceptors → Hypothalamus & pituitary glands → Alter water reabsorption

When water level decreases in human body

1. Increase in osmolality of blood → Stimulate osmoreceptors present in hypothalamus → 1. Cause release of anti-diuretic hormone (ADH) → Re absorption of H2O in kidneys → Urine output reduced

2. Decrease in blood pressure and blood volume → stimulate baroreceptors present on arteries and kidneys to release renin → Renin causes release of Aldosterone → Aldosterone causes to reabsorption of Na+ of excretion of K+ → Increase blood pressure & volume

Chapter 6E - Malfunctioning of homeostasis

Diabetes Mellitus have either Type 1 or Type 2

Type 1 (Autoimmune disease) → Immunity destroys Beta cells in pancreas (responsible for secreting insulin) → Blood glucose level with increase. (Hyperglycaemia)

People with type 1 diabetes produce little to no insulin which is caused by autoimmune disease where cytotoxic C cells (CT - white blood cells that kills body cells infected by a specific virus) target and destroy beta cells in the islets of Langerhans

Type 2 ( (Lifestyle & genetic predispositions)

1. Beta cells are not producing enough insulin → Blood glucose level will increase (Hyperglycaemia)

2. Muscle cell, liver cells they become resistant to insulin → Blood glucose level will increase (Hyperglycaemia)

Hyperglycaemia blood glucose levels >78

Hypoglycaemia blood glucose level less than <4

Symptoms

1. Frequent urination

2. Excessive thirst

3. Excessive hunger

4. Weight loss

5. Lethargic

6. Vision impaired

7. Numbness and tingling in legs

8. Delayed wound healing

You can take insulin shots to treat type 1 diabetes but there are side effects of hypoglycaemia

Hyperthyroidism

Location - Thyroid gland is present at the base of neck.

1. T3

2. T4 (Hormones are made up of iodine & tyrosine)

Thyroid hormones:

1. BMR

2. Nutrients metabolism

3. Heart rate

4. Respiratory rate

5. Reproduction

6. Regulates muscle tone

Hypothalamus → Thyrotropin releasing hormones (TRH) → Anterior pitutary gland → TSH (Thyroid stimulating hormone) → Thyroid gland → T3 (sends negative feedback) or T4

To get rid of hyperthyroidism you can:

• Surgery (removal of thyroid gland)

• Radioactive iodine

• Medicines like B-blockers