Nutrient and Gas Requirements

IQ: What difference in nutrient in gas requirements between autotrophs and heterotrophs

Leaf function

photosynthesis occurs here - produces glucose

Leaf structure

leaves are green as they contain chlorophyll. Tend to be flat, thin and broad to maximize surface area for sunlight. Contain guard cells which open and close on the underside of the leaf to enable carbon dioxide.

Stem function

supports the plant (like a skeleton). Acts as a conduit for the transport of food and water around the plant.

Stem structure

Made up of ground tissues, and vascular bundles (phloem and xylem).

Roots function

anchors the plants in the soil, absorb water, uptake nutrients from the soil and can act as storage. Water gets in through osmosis.

Root structure

underground and usually branch out to a large surface area (sa:v ratio)

Vascular bundle

xylem - water, phloem - sugar

technology to examine plants

1. MRI
2. X-ray computed microtomography

How MRI’s work

* radiowaves blast the sample and a magnetic field is generated aligning all atoms of the plant
* Produces a series of images that can be used with a computer to construct a 3D image of the surface

Xray computed microtomography

* A sample is positioned in an x-ray beam and bombarded with x-rays
* The scatter of these x-rays is collected to produce hundreds of images – which are analysed and reconstructed into an image
* Provides detail on the spatial arrangement of internal tissues of the plant as a 3D image

Products of photosynthesis

water, sunlight, carbon dioxide

Source of water for photosynthesis

obtained through osmosis in the roots and travels up through the xylem to the leaves

source of sunlight for photosynthesis

Available from the sun which provides energy in for photosynthesis

Carbon dioxide source for photosynthesis

enters through the stomata on the underside of the leaf

Adaptations to absorb CO2

* thin = less distance to travel
* lots of air spaces
* Covered in stomates

Waste products destination

oxygen → released into air

glucose → loaded into phloem and move around the entire cell.

Gas exchange

exchange of oxygen and carbon dioxide between an organism or cell and the environment

efficient gas exchange requirements

1. large SA
2. Moist gas exchange surface
3. Close contact

Gas Exchange in plants

1. Stomates allow water to evaporate and CO2 to diffuse into leaf for photosynthesis and O2 diffuse out of leaf into the air.
2. Guard cells change shape to control the opening and closing. Hydrated (they look like kidney beans and allow gas exchange), dehydrated (flatten out and clsoe the gap, stopping exchange).
3. Lenticels - gaps in the stem and trunk of trees


1. root hairs - increase surface area of roots

Organs for gas exchange

trachea → lungs → bronchi → bronchiole → alveoli

lungs structure + function

sponge like - allow for diffusion

trachea structure + function

soft, flexible which means it can’t kick and block air flow.

Bronchi/Bronchus structure + function

carry air to each lung

Alveoli structure + function

tiny air sacs, wrapped by a capillary. close contact to blood allows for gas to diffuse easily. Surface is always moist.

Breathing

Inhale: diaphragm decrease, volume increase

exhale: diaphragm increase, volume decrease

Digestion

the breaking down of large and complex food particles into much smaller particles that can be absorbed through the intestinal wall and into the bloodstream.

types of digestion

mechanical (physical breaking down) and chemical (broken down by chemicals)

Digestive system order

mouth → saliva glands → oesophagus → liver → stomach → gall bladder → pancreas → small intestine → villi → large intestine

mouth

* mechanical
* different teeth have different functions (bite, tear, crush)

Saliva glands

* chemical
* contains enzymes, mixes with food and acts as a lubricant

Oesophagus

* mechanical
* made up of muscles which use peristalsis to transport food from mouth to the stomach

Stomach

* chemical + mechanical
* muscular sac
* acts as a ‘storage’ organ
* gastric ‘juices’ break down larger molecules

Pancreas

* chemical digestion
* produces pancreatic ‘juice’ which contains enzymes
* pancreatic acid is added into the start of the small intestine

Liver

* chemical digestion
* produces bile which emulsifies lipids but isn’t an enzyme
* can store products of digestion like glycogen.

Gall bladder

* chemical
* stores bile which is added to duodenum

Small intestine

* chemical
* 2cm wide and 7m long tube
* absorbs nutrients into bloodstream
* produces enzymes to digest carbs, proteins and lipids
* glucose and amino acids are absorbed into capillaries
* have villi

Villi

* contained in small intestine
* hair like projectiosn
* increase surface area
* contain blood vessels which products diffuse into

large intestine

* undigested and unabsorbed food passes in here
* excess water, minerals and vitamins are absorbed
* undigested material, bacteria, water and sats form faeces which is eliminated through the digestive passage.

Protein ( absorption)

==Broken into== → amino acids

==Absorbed where== → villi in small intestine

==what produces the enzyme== → protease (stomach, pancreas and intestine wall)

carbohydrates (absorption)

==Broken into== → simple sugars

==Absorbed where== → villi in small intestine

==what produces the enzyme== → amylase (saliva glands)

lipids (absorption)

==Broken into== → fatty acids and glycerol

==Absorbed where== → small intestine

==what produces the enzyme== → lipase (stomach and pancreas)

water (absorption)

Absorbed: small intestine

Waste: excreted in urine

Vitamins and mineral (absorption)

Absorbed: small intestine

Stored: in liver

Autotroph energy or nutrient requirements

light for photosynthesis

Autotroph simple chemical requirements

water and carbon dioxide → photosynthesis

oxygen → respiration

minerals (nitrates, phosphates and sulfates)

Autotrophs waste removal needs

Oxygen → simple diffusion → stomates

salt may be excreted

Heterotroph energy or nutrient requirements

complex high energy carbs, proteins and lipids produced by other organisms

Heterotroph simple chemical requirements

water → body functions

Oxygen → respiration

additional vitamins and minerals

Heterotroph waste removal needs

CO2 → excreted by cells by diffusion

Urea → excreted through urine

Transport system requirements

1. system of vessels
2. transport medium
3. driving mechanism to ensure substances in correct direction.

Gas Exchange mammals summary

Oxygen is carried in through air, the oxygen travels in through the nose/mouth then the trachea into the bronchus, brionchiole and into alveoli where gas exchange takes place. Oxygen diffuses into the capillary and CO2 diffuses out.

Gas exchange mammals SA

provided through bronchi which branch far out.

gas exchange mammals moist surface

thin film of liquid surrounding alveoli

Gas exchange Insects summary

The oxygen enters in through openings called spiracles, and goes into a series of tubes called the tracheae and tracheoles. The oxygen then diffuse directly to the body cells as they are close to a trachea tube.

Gas Exchange Insects SA

The network of tubes increase the surface area. As they are so small it means they have a super efficient SA:V ratio and gas exchange occurs almost instantly.

Gas Exchange Insects moisture

trachea tubes are moist inside

Gas Exchange Fish

Water (with oxygen dissolved in) enters through the mouth and flow in the direction past the gills. Gills are made up of filaments which are made up of lamella. Lamella contain capillaries which the oxygen can diffuse into due to close contact, with the water and blood flowing in opposite directions and creating a concentration gradient.

Gas Exchange Fish SA

gills are made up of capillaries and filaments, with water flowng through. Gills are feather like and have finely divided surfaces to maximise SA contact with water.

Gas Exchange Fish Moist

The transport medium is water.

Xylem (substance, structure, function)

^^substance^^: water and mineral ions

^^structure^^: made of dead, hollow cells, that form a continuous pathway. Contains ‘lignin’ which makes it impermeable to water.

^^Function^^: transports water and ion through transpiration-cohesion theory as water molecules are attracted to walls of xylem.

transpiration-cohesion-tension theory

water molecules are polar, and are attracted to the walls of xylem. As water evaporates through stomatas, due to molecules all being attracted to each other, the water molecules are ‘pulled up’ towards and out of the leaves.

Phloem (substance, structure, function)

Substance: nutrients and organic sugars

Function: transport and distribute organic nutrients

Structure: made of sieve tube cells and companion cells

sieve tube cell

thin phloem cells with large perforations called sieve plates, which allow fluid to flow.

companion cells

load and unloaded sugars into the cavity of the sieve tube members( provides ATP)

Translocation

**Source to Sink**


1. sugars produced in leaves/source cell (respiration)
2. sugar loaded into phloem/sieve tube members via active transport, with atp provided by companion cells. water follows by osmosis
3. sugar solution flows due to the pressure differential to areas of low sugar, where it is unloaded at the sink cell, and water returns to the source via the xylem.

Plant theories to prove photosynthesis

1. Bensen and Calvin- carbon tracing
2. Van Helmont - Plant mass over time
3. Priestley - dead mouse experiment
4. Jan IngenHousz- plants in water

Bensen and Calvin- carbon tracing experiment

Leaf is given CO2 containing Carbon 14 → Co2 converted to glucose through photosynthesis → carbon-14 is found in the sugar, proving the process

Van Helmont - Plant mass over time

Planted a willow tree and weighed the dry soil → watered the plants and observed over 5 years → reweighed tree, mass increase, soil stayed the same

Priestley - dead mouse experiment

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Jan IngenHousz- plants in water

submerged plants in water, obvserved bubbles appearing on underside of leaves and green parts. Taught us green part produces oxygen in the da.

Label A and B

A: Xylem

B: Phloem

Label A and B

A: Xylem

B: Phloem

Types of Circulatory systems

Closed (high pressure) and Open (low pressure)

Close circulatory system

transport medium is contained/enclosed in vessels at all times.

→ vertebrates like humans

Open circulatory systems

the transport fluid leaves the vessels to bein direct contact with organs.

→ invertebrates

Reasons for different types

* SAP V ratio (invertebrates are smaller so open system can meet the needs)
* Open systems are less efficient but okay with a high SA:V ratio.

Function of human circulatory system

to pump blood containing oxygen, glucose, amino acids to cells and provide a medium for wastes such as urea and CO2 to be removed. Blood = transport medium.

Atrium

pumps blood into ventricles

Ventricles \[Right and Left\]

Right pumps blood to lungs

Left pumps blood away from lungs

NOTE: right and left are swapped

valve

prevents backward flow of blood

Aorta

largest artery which carries oxygenated blood to from heart to circulatory system

Pulmonary vein

carry oxygenated blood to left atrium

Pulmonary Artery

carry oxygen poor blood from heart to lungs

Left side of heart

oxygenated bloodR

Right side of heart

poor oxygen blood

Arteries function

carry blood away from heart

arteries structure

thick, muscular walls which minimises tearing when blood is pushed along. They branch out and get smaller, called arterioles

Veins function

carry blood back to heart (deoxygenated)

Veins structure

thin walls and have valves which prevent backward flow of blood. Branch from veins into venules than capillaries.

Capillaries function

tiny blood vessels which form a network through tissues so every living cell from blood to cells.

Capillaries structure

walls of capillaries are one cell thick, which enables diffusion to occur, especially with oxygen and CO2 in the alveoli.

Blood

transport medium, bodily fluid that delivers nutrients and oxygen around the body and carries wastes to where they are to be removed.

Red blood cells

primary function is to carry oxygen - gaemoglobin (protein). Produced in bone marrow

White blood cells

protect the body against diseases by producing antibodies and destroying foreign invaders. Many types. p

platelets

clump together to form clots preventing blood loss

plasma

fluid component of the blood that is mostly water and dissolved substances e.g: Co2, oxygen, wastes, hormones etc.

Composition of blood change in Heart

Oxygen + glucose **decrease**

Carbon dioxide + Urea **increase**

Composition of blood change in Brain

Oxygen + glucose **decrease**

Carbon dioxide + Urea **increase**

Composition of blood change in Lungs

Oxygen + Urea **increases**

Glucose + Carbon Dioxide **decreases**

Composition of blood change in Kidney

Carbon dioxide **increases**

Glucose + Urea + Oxygen **decreases**