Biology

List 4 adaptations of the alevoli

1. Large surface area for gas exchange

2. Thin walls (one cell thick) for faster diffusion

3. Moist walls to enhance gas exchange

4. Rich blood supply for quick transport of air

5. Ventilation maintains concentration gradient

6. Elastic fibers that help them stretch during inhalation and recoil during exhalation.

Consequences of smoking

1.Carbon monoxide binds with haemoglobin , preventing it from binding with oxygen , leading to parts of the body not receiving enough oxygen for respiration.

2.Tar paralyzes and destroys cilia in the trachea and bronchi leading to mucus and dust to accumulate causing ‘smokers cough’

3.Chemicals like nicotine can cause a build up of fatty deposits on the walls of the coronary arteries. This narrows the arteries , restricting blood flow to the heart muscle cells.

4. Smoke particles destroy walls of alveoli , leading a decrease in surface area for diffusion.

Adaptations of a leaf for gas exchange

• short diffusion distance

• large surface area

• They have many stomata which allow movement of gases in and out of the air spaces by diffusion

• Air spaces to allow gas movement around the loosely packed mesophyll cells

• Many stomata in the lower epidermis open in sunlight to allow gas movement in and out of the leaf

• Thin cell walls allow gases to move into the cells easily

• Moist air which gases can dissolve into for easier movement into and out of cells

Order of respiratory sysytem

• the trachea 

• the bronchi

• the bronchioles

• the alveoli

adaptations of respiratory system

• Large surface area - provided by many alveoli, increasing the area over which gases can be exchanged by diffusion between air in the lungs and blood in the capillaries.

• The walls of the alveoli and capillaries supplying blood to them are one cell thick, keeping the distance over which gases are exchanged as short as possible.

• Good ventilation with air - movement of air in and out of the lungs maintains a high concentration gradient for oxygen and carbon dioxide between the air in the lungs and blood in the capillaries.

• Good blood supply - maintains a high concentration gradient by carrying blood with a high concentration of oxygen away from the alveoli.

• Moist walls help CO2 and oxygen dissolve first , increasing rate of diffusion.

Describe what happens when you breathe in:

External intercostal muscles contract.

Ribcage moves up and out

Diaphragm contracts and flattens

Volume of thorax increases

Pressure in thorax decreases

Air drawn in.

Describe what happens when you breathe in:

External intercostal muscles relax.

Ribcage moves down and in

Diaphragm relaxes and becomes dome shaped

Volume of thorax decreases

Pressure in thorax decreases

Air is forced out.

Effect of tar on lungs

• is a carcinogen linked to increased chances of cancerous cells developing in the lungs

• damages the lungs by paralyzing cilia, which can cause dust and bacteria to accumulate in trachea and bronchi

Effect of carbon monoxide on lungs

• binds irreversibly to haemoglobin, reducing the capacity of blood to carry oxygen

• puts more strain on the breathing system, as breathing frequency and depth need to increase to supply the same amount of oxygen

• means that the circulatory system needs to pump blood faster, raising blood pressure and increasing the risk of coronary heart disease and stroke

effect of nicotine on lungs

• narrows blood vessels and increases heart rate, leading to increased blood pressure

• causes high blood pressure that leads to blood clots forming in the arteries, potentially resulting in heart attack or stroke

Chronic bronchitis

• Tar stimulates goblet cells and mucus glands to enlarge and produce more mucus

• Mucus builds up, blocking the smallest bronchioles and leading to infections

  • The build-up of mucus can result in damage to the cilia, preventing them from beating and removing the mucus

• A smoker's cough is the attempt to move the mucus

effects of emphysyma

• Emphysema develops as follows:

  • an enzyme breaks down the elastic fibres in the alveoli

  • the alveoli become less elastic and cannot stretch, so many burst

  • the breakdown of alveoli reduces the surface area for gas exchange

Practical: The Effect of Physical Activity on Breathing

C-Start and end of physical activity

O-Human participants from similar age groups

R-use multiple participants and calculate a mean

M1-Measure breaths per minute before exercise

M2-Measure breaths per minute after exercise

S- Type of physical activity , method of counting breaths

gas exchange during the day

The plant photosynthesizes more then it respires during the day

Light available

Oxygen made by cells is released

CO2 enters cells.

more stomata open as light causes them to open

gas exchange during the night

The plant respires more then it photosynthesizes during the night

No light

Co2 made during respiration released

Oxygen used in respiration

No change in nitrogen

How does gaurd cells open and close

Open

• Water and air enter from stomatal pore

• stomata opens when water moves in to guard cells through osmosis causing cells to become turgid .

• Allows gases to diffuses

• tens to open when plenty of water and light

Close

• guard cells lose water to epidermal cells by osmosis causing them to become flaccid

• This prevents any diffusion into or out of the leaf

• Stomata tend to close due to low water availability or low sunlight

Practical : effect of light on gas exchange

C-Availability of light

O-Leaves of the same size

R-repeat severeal times to ensure reliable results

M-Observe change in hydrogen carbonate indicator colour

M-Overnight

S-same volume of hydrogen carbonate indicator , same temperature.

Describe the biological consequences of cigarette smoking on the human lungs.

1.Emphasyma - Damages alveoli

2.Tar damages cilia, which allows bacteria and dust to infiltrate the airways, causing mucus to build up.

3.Contains carcinogens

order of photosynthesis

• Energy from sunlight is absorbed by chlorophyll, a green pigment found inside chloroplasts

• Green plants use this energy to make the carbohydrate glucose from the raw materials carbon dioxide and water

• At the same time, oxygen is made and released as a waste product

products of photosynthesis

• Plants use the glucose they make as a source of energy in respiration

• They can also use it to

  • Produce starch for storage

  • Synthesise lipids for an energy source in seeds

  • To form cellulose to make cell walls

  • Produce amino acids (used to make proteins) when combined with nitrogen and other mineral ions absorbed by roots

raw materials for photosynthesis

CO2 + H2O

limiting factors

• Temperature

• Light intensity

• Carbon dioxide concentration

effect of higher temp on photosynthesis

Higher temperature means partcles have more energy so more successful collisions between substrates and enzymes which results in formation of product.

However too high temp can denature enzymes , which means it can not bind with the subtrate which reduces the overall rate of photosynthesis.

effect of light intensity on phtoosyntehsis

The hgiher the light intensity , the mroe enrgy the plant has , so the rate of photosynthesis is faster. This will continue until another factor is limiting.

Co2 effect on phtosynthesis

More CO2 means the recation can occur faster until another factor is limiting

what is magenium needed for?

to make chlorophyll (defienciency can cause yellowing)

nitrate

source of nitrogen to make amino acids (can stunt growth if deficeincy)

Practical: Investigating Light & Photosynthesis

• C - changing whether there is light or no light onto the leaf (cover a aprt with aluminium.

• O - leaves will be taken from the same plant or same species, age and size of the plant

• R - repeat the investigation several times to ensure our results are reliable

• M1 - observe the colour change of the leaf when iodine is applied

• M2 - ...after 1 day

• S - control the temperature of the room

Practical: Investigating Carbon Dioxide & Photosynthesis

• C - We are changing whether there is carbon dioxide or no carbon dioxide

• O - The leaves will be taken from the same plant or same species, age and size of plant

• R - We will repeat the investigation several times to ensure our results are reliable

• M1 - We will observe the colour change of the leaf when iodine is applied

• M2 - ...after 1 day or after several hours in bright light

• S - We will control the temperature of the room and the light intensity

What are carbohydrates/glucose made of

Hydrogen , oxygen , carbon

What are lipids made of

Fatty aicds , glycerol , Hydrogen , oxygen , carbon , (sometimes phosporus)

what are proteins amde of

Amino acids-Hydrogen , oxygen , carbon , nitrogen , (soemtimes sulfur)

What causes starvation

Taking in less energy then being used. Body rbeaks down energy stores. first fat then muscles causing weight loss. can damage heart and immune system

coronary heart disease

diet has too much staurated fat and cholestrol. cause fatty deposits to build up in up in arteries which reduces blood flow to heart muscle cells which depreives them of oxygen can cause heart attacks.