Alexander Appel is dumb

What does MRS GRENC stand for?

Movement, respiration, sensitivity, growth, reproduction, excretion, nutrition and control.

Where is the DNA in prokaryotic cells'?

. The DNA is free in the cytoplasm.

How do Prokaryotic cells produce energy?

They produce produce energy through the enzymes on their cytoplasm.

What are pathogens?

Microorganisms that cause disease by disrupting normal body functions.

What type of pathogens are there?

There is bacteria, virus, fungi, parasite and protists.

Give an example for each pathogen type.

Fungi: Athlete’s foot

Bacteria: Cholera

Virus: Covid-19

Protists: Malaria

Parasite: Tapeworm

Why are viruses considered non-living'?

Viruses don’t carry out cellular respiration, excretion and don’t respond to stimuli.

What are all the organelles, plants & animal and their functions?

-Nucleus: Controlls the cell and stores DNA

-Cytoplasm: Contains enzymes and is where chemical reactions occur, also anaerobic respiration.

-Cell membrane: Controlls what gets in and out of the cell

-Mitachondria: Produces energy through aerobic respiration

-Ribosomes: synthezises protein

-Cell wall: Protection

-Vacuole: Stores water, nutrients and waste products.

-Chloroplasts (chlorophyll): Where photosynthesis occurrs.

What does Starch, Proteins and Fats convert to and what enzyme is implicated in the process of each one?

Starch to glucose, catalyzed by Amylase

Proteins to Amino Acids, catalyzed by Protease

Fats to Fatty acids and glycerol, catalyzed by Lipase

Differences of Polymers from Monomers.

Polymers are bigger, is composed of monomers and is insoluble. Monomers are smaller and soluble.

What order of organs are included in the digestive process?

Mouth-Oesophagus-Stomach-Duodenum-Ileum-Large Intestine-Rectum-Anus.

What is used to test Starch, sugar, lipid and protein? (si les bepb

Starch: Iodine

Lipid: Ethanol

Protein: Biuret

Sugar: Benedicts

What colour indicates that a Starch, Sugar, Lipid or protein test is negative or positive?

Positive Starch: blue-black

Negative Starch: Orange-brown

Positive Sugar: Brick-red

Negative Sugar: Light blue

Positive Lipid: Cloudy

Negative Lipid: Colourless

Positive Protein: Purple

Negative Protein: Blue

What do enzymes do?

Break down large molecules to smaller molecules, replicates DNA and speeds up some body processes.

What is the effect of temperature in enzymes?

Enzymes work faster at a higher temperature, but when a point is reached, the active site starts to change shape. This could mean the enzyme wouldn’t be able to bind to the subtrate, so it’s officially denatured.

What is Osmosis?

When a solvent moves through a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration

What is diffusion?

The process of molecules moving from high molecule concentration to a low molecule concentration driven by the concentration gradient to achieve equilibrium.

What is active transport?

Active transport is whensubstances travel from an area of low concentration to high concentration, against the concentration gradient.

What is the word equation for photosynthesis?

Carbon dioxide + Water —*light*—> Glucose + oxygen

Why is chlorophyll important for photosynthesis?

It absorbs the light energy required.

Name every food group and their function.

Carbohydrate: Main energy source

Proteins: Builds and repairs tissues

Fats: Provides insulation

Vitamin A: Improves vision

Vitamin C: Prevents scurvy

Vitamin D: Needed to absorb calcium.

Calcium: Strengthens teeths and bones

Iron: Makes haemoglobin for healthy blood

Fibre: Aid the movement of food through the gut

Water: Mantains the body hydrated.

What is peristalsis?

It’s the wave-like contraction that pushes the food through the digestive system.

How is the small intestine adapted to absorption?

The small intestine has villi and microvilli, which increase surface area for absorption. Thin walls and a rich blood supply allow quick diffusion of nutrients into the bloodstream. Nutrients are absorbed efficiently through diffusion and active transport.

What nutrients does the villi and microvilli absorb?

Villi: main nurtients like glucose, amino acids and fatty acids

Microvilli: Less important nutrients like electrolytes or vitamins.

Which living things are eukaryotic and which is prokaryotic?

Prokaryotic: Bacteria

Eukaryotic: Plants, Animals, fungi and protoctists.

Which living things are single-celled and multicellular?

Multicellular: Plants, Animals and some fungi (Mucor)

Single-celled: Fungi (yeast), protoctists and bacteria.

What is the cell wall made of? (plants and fungi)

Plants: Cellulose

Fungi: Chitin.

How do fungi, plants and animals store carbohydrates?

Fungi: Glycogen

Plants: Starch or Sucrose

Animals: Glycogen

How do fungi make the process of nutrition?

By Saprotrophic nutrition, which involves secreting extracellular enzymes outside the body to break down food for nutrient absorption.

The multicellular fungi have a body called what and what is it made up of?

It’s called a mycelium and it’s made of hyphae, which contains lots of nuclei.

Give an example of a virus that affects plants.

tobbaco mosaic virus- stops plants from producing chlorpplasts.

Give two examples of a specialised cell.

Red blood cell and sperm cell.

What is a stem cell?

A stem cell is an undifferientated cell that can specialise into other cell types.

How can stem cells be used in medicine?

Stem cells can be injected into a damaged tissue to replace dead cells, for example, replacing skin cells to treat burns.

Give one advantadge and one disadvantadge of using stem cells in medicine.

Helps sick people live a healthy and normal life, breaks the rights of the human the embryo would be.

In the body, where can stem cells be found?

In bone marrow.

What is a catalyst?

A catalyst is a substance that increases the speed of reaction without being consumed or permanently altered.

What’s a subtrate?

A molecule that is changed in a reaction.

What’s an active site?

The part where a subtrate joins on the enzyme.

How many reactions do enzymes speed up? (usually)

One

Describe the temperature enzyme practical.

Mix amylase and starch and start a timer. Remove a few drops from the mixture every 10 seconds and add it to iodine. The orange colour will turn black, and when it stops turning black, record the total time taken. Repeat at different temperatures to see how it affects the time taken for the starch to be broken down.

Describe the osmosis practical.

Cut a potato into identical cylinders, weigh themand put them in sugar solutions of varying concentrations. After determined time, reweigh them and calculate the % change in mass, If the potato has absorbed water, it’ll increase. If it has been drawn out, it’ll decrease.

What will happen tot he mass of a piece of potato added to a concentrated sugar solution?

It will decrease, as water will move out of the potato cells into the sugar solution.

What’s the balanced symbol equation of photosyntheiss?

6CO2​+6H2​O———C6​H12​O6​+6O2​ (reverse for respiration)

Name 6parts of the leaf structure and their function. (SPUWGS)

Waxy cuticle: waterproof to stop water loss.

Upper epidermis: transparent to let sunlight through.

Palisade mesophyll: packed with chloroplasts, where most of the photosynthesis occurrs.

Spongey mesohpyll: Gaps to facilitate gas exchange

Guard cell: controls rate of gases entering and exiting through stomata.

Stomata: Holes in lower epidermis to allow gases in and out.

How is the leaf adapted for photosyntheiss (4 points)

A thin surface speeds up the diffusion of gases, like carbon dioxide, into leaf cells

A broad, flat shape provides a large surface area to absorb more sunlight.

Upper epidermis transparent to let light through.

Waxy cuticle waterprof to prevent water loss.

Describe the practical to test a leaf for starch

Boil the leaf to stop any chemical reactions, place it in ethanol to remove the chlorophyll and rins it in warm water to soften it. Add iodine solution to the leaf. If starch is present, it’ll turn blue-black.

What’s the function of the bile

It neutralises the acid (as it’s alkiline) and makes the conditions alkiline, where the enzymes work best. It also emulsifies fats, which makes the digestion faster.

Where is the bile produced and stored.

It’s produced in the liver and stored in the gall bladder.

What is ATP?

It’s a substance that stores the energy needed for many cell processes

Which of the two types of respiration is used most of the time and how many molecules of ATP does it produce per molecule of glucose.

Aerobic, 32.

When does the body use anaerobic respiration?

When you do vigorous excercise and your body can’t supply enough oxygen to your muscles for aerobic respiration, so it has to do both.

How many molecules of ATP are producs in anaerobic respiration?

2

What is broken and produced in anaerobic respiration?

Glucose is partially broken down and lactic acid is produed, which is build up in muscles and can lead to cramps.

What’s the word equation for anaerobic respiration in animals?

Glucose——- lactic acid (+ energy)

What’s the word equation of anaerobic respiration in plants?

Glucose—— ethanol + carbon dioxide (+energy)

How can you investigate how pH affects enzyme activity?

Mix amylase and starch with a buffer solution at different pH levels. Every 10 seconds, add a few drops of the mixture to iodine. The solution will turn black, and once it stops, record the time taken. Do the same with the other mixtures

How do you measure the energy from food?

Get a dry food

What organelles does a bacteria cell have

Cytoplasm, cell membrane cricular chromosome of DNA

How can you test the production of co2? (beans)

Using a hydrogen-carbonate indicatori, which will convert to yellow in the presence of co2.

Boil beans to kill them and soak water in other ones so they start to germinate after a day or two.

Place a platform between the beans and the indicator and seal the tube.After a few hours, come back and the tube with the germinated beans will have a yellow liquid beneath it.

How can you test that respiration produced heat?

Boil beans to kill them and soak others to start germination. Place the germinating beans in a vacuum flask with air for aerobic respiration. Add a thermometer, seal the flask, and record the temperature daily for a week. Repeat the process multiple times and calculate the mean final temperature. The flask with germinating beans should have a higher final temperature than the boiled beans.

What’s the role of diffusion in gas exchange in a plant?

During photosynthesis, CO2 moves into the leaf from the air via diffusion, as its concentration is lower inside the leaf. Similarly, O2, a waste product, diffuses out of the leaf, from a higher concentration inside to a lower concentration in the air.

How does the net exchange of gases depend on light intensity?

At higher light intensity, plants photosynthesize more, producing excess oxygen and absorbing more CO2 than they release. At night, with no light, plants can only respire, taking in oxygen and releasing CO2."

How is the structure of the leaf adapted for gas exchange? (3 points)

-Broad, so larger surface area for diffusion.

-Thin,s o gases only have to travel a short distance to reach the cells where they’re needed.

-Air spaces inside the leaf let gases like carbon dioxide and oxygen move easily between cells.

How is the stomata adapted for gas exchange (3 points)

-Closes as it gets dark because photosynthesis isn’t possible so that water can’t escape.

-Closes when supplies of water get lower, which stops the plant from photosynthesising but also prevents it from dying.

-Direct pathway for diffusion for gases like CO2 and o"2

How can you show how light intensity affects net gas exchange?

Place hydrogen-carbonate indicator in 4 test tubes, adding a healthy leaf to three and leaving one as a control. Wrap one leaf in gauze, another in foil, and leave one uncovered. Place the tubes in bright light. After some time, observe the indicator:

• No change in the control.

• The foil-covered leaf turns yellow (no photosynthesis).

• The gauze-covered leaf remains the same (CO2 absorption and production balance).

• The uncovered leaf turns purple (high photosynthesis, absorbing more CO2).

Describe the structure of the thorax

"The thorax is the upper part of the body, separated by the diaphragm. Inside, the lungs are surrounded by pleural membranes, and intercostal muscles run between the ribs. Air enters through the trachea, which splits into two bronchi, then into smaller bronchioles that end in alveoli, where gas exchange occurs."

What’s the role of the intercostal muscles and diaphragm in ventilation (breathing in and out)

When you inhale, the intercostal muscles and diaphragm contract, the thorax volume increases which lowers the pressure and draws air in.

When you exhale, intercostal muscles and the diaphragm relax, the thorax volum decreases, forcing the air out.

How does the alveoli cary out gas exchange in the body?

"The blood near the alveoli has high CO2 and low oxygen levels. Oxygen diffuses from the alveolus into the blood, while CO2 diffuses from the blood into the alveolus to be exhaled."

After the alveolus carries out gas exchange in the body and blood cells reaches the body cells, what happens?

Oxygen is released from the red blood cells and diffuses into the body cells and carbon dioxide diffuses out of the body cells into the blood and is carried back to the lungs.

How is the alveoli adapted for gas exhcange?

the large number of alveoli gives the lungs a big surface area.

-Moist lining for gases to dissolve in.

-one cell thick walls so the gases don’t have far to diffuse.

-Great blood supply to mantain a high concentration gradient.

-permeable so gases can diffuse across easily.

How can smoking affect the lungs and circulatory system?

Smoking damages the alveolar walls, reducing the surface area for gas exchange, which affects oxygen uptake. Tar in cigarettes harms the cilia in the lungs and trachea, making it harder to clear mucus and trapping bacteria, which increases the risk of chest infections. Tobacco contains carcinogens that can lead to cancer. Carbon monoxide in cigarette smoke reduces blood oxygen levels, raising blood pressure and heart rate, which can damage artery walls, increase the risk of blood clots, and lead to coronary heart disease

how can you investigate the effect of excercise on breathing rate and why the result is what it is?

Sit still for 5 minutes and count the number of breaths taken in one minute. Then, run for 4 minutes and count your breaths a minute after. Repeat the process and calculate the mean. The number of breaths after exercise should be higher because muscles respire more during exercise.

How can you investigate the release of co2 in your breath?

Set up two boiling tubes with limewater. After breathing out through one of the straws, it should become cloduy to the prescence of CO2, but after breathing in and absorbing the CO2, the limewater should eventually become colourless, as the air in the room doesn’t have nough CO2 to convert it to cloudy.

What mineral ions are needed for plants?

They’re all neded for growth

-Magnesium ions: For chlorophyll

-Nitrate ions: needed to synthezise amino acids

What do viruses have in terms of structure?

They have a protain coat and one type of nuclic acid (RNA or DNA)

image size?

actual size x magnification

E=???

Mass x change in temperature x 4.2