Biology Chapter 1 (Cells) and 2 (movement of substances.)

This chapter is the easiest chapter of the whole year.

What is the function of the nucleus?

The nucleus controls all cell activities. The nucleus also contains chromatin. The nucleus also

What is the function of the mitochondria

The mitochondria is the site where aerobic respiration takes place to produce energy for cell activities. Oxygen is usually taken in to produce energy.

What does the Golgi Body do in a cell?

The Golgi body helps to store and package substances in vesicles from the endoplasmic reticulums. The Golgi body also helps to modify substances from the ER.

What is the function of a vacuole and what does it contain?

The vacuole helps to store mineral salts and water in the cell. The vacuole contains cell sap that comprises of nutrients and minerals salts for example : sugars.

What does the smooth endoplasmic reticulum in a cell do?

The smooth endoplasmic reticulum helps to turn harmful substances into harmless substances that can be used in the cell. This process is called detoxification.

Why is the RER rough?

The rough endoplasmic reticulum has a rough exterior as ribosomes are attached to it.

How are vesicles secreted out of the cell?

The vesicles from the smooth endoplasmic reticulum pinch off from the ER , and fuse to the Golgi Body. The Golgi body the modifies the substances and packages them into small vesicles for secretion out of the cell. The secretory vesicles from the Golgi Body then pinch off and get transported out of the cell or be used within the cell.

What does a cytoplasm do ?

The cytoplasm is a jelly-like substance and the site where many chemical reactions take place. It also acts as a solvent.

What is the function of the ribosomes in a cell?

Ribosome help to synthesise proteins in the cell that may be used within the cell or transported out of the cell.

Why is the rough endoplasmic reticulum rough?

The rough endoplasmic reticulum is rough as there are ribosomes attached to the outer surface of the rough endoplasmic reticulum.

What is a cell wall and its function?

A cell wall is a fully permeable membrane that helps to maintain the regular shape of as plant cell and protects the cell from bursting.

What is crenation?

Crenation is when tiny little spikes form on the surface of an animal cell.

Describe what happens to a plant cell when it is placed in a lower water potential solution.

The cell sap in the plant cell has higher water potential compared to the lower water potential solution. Water moves out of the cell through osmosis. The water travels from a region of higher water potential to a region of lower water potential down at water potential gradient. Hence the cell would become plasmolysed as the cell membrane shrinks and separates from the cell wall while the vacuole shrinks in size.

Describe what’s happens to a red blood cell when it is placed in a higher water potential solution.

The red blood cell would swell up and burst due to the surrounding water having a higher water potential solution than the red blood cell. Hence water moved into the cell through osmosis and the cell burst due to the absence of the cell wall in animal cells.

Describe what happens to a plant cell when it’s placed in a higher water potential solution.

The plant cell becomes turgid. The cell sap in the plant cell has lower water potential compared to the surrounding water which has higher water potential. Water moved into the cell through osmosis. The water molecules moved from a region of higher water potential to a region of lower water potential down a water potential gradient. The cell membrane of the plant cell then pressed up against the cell wall and the vacuole increased in the size. The plant cell swelled up and become turgid.

Describe what happens to a red blood cell when it is placed in lower water potential solution.

When a red blood cell is placed in a lower water potential solution , there is higher water potential in the cell compared to the solution. Water moves out of the cell by osmosis as water move from a region of higher water potential to a region of lower water potential down a water potential gradient. Hence the red blood cell becomes cremated and tiny spikes form on the outside of the cell.

Define turgidity in a plant cell.

turgidity is the amount of turgid pressure that is within a cell

Describe plasmolysis.

Plasmolysis is when the cell membrane of a cell shrinks away from the cell wall and the vacuole decreases in size.

What is diffusion?

Diffusion is the process where particles move from a region of higher concentration to a region of lower concentration down a concentration gradient.

What is Osmosis?

Osmosis is the process where water molecules move from a region of higher water potential to an area of lower water potential down a water potential gradient.

What is active transport?

Active transport is the process where energy is taken up to move particles from an area of lower concentration to an area of higher concentration against a concentration gradient.

What is need for active transport to take place?

Oxygen. Typically occurs in a root hair cell.

What are the adaptations of a red blood cell?

The red blood cell is elastic which allows it to go through the lumen of capillaries. The red blood cell lacks a nucleus in order to store more haemoglobin to transport more oxygen around the body. The red blood cell contains haemoglobin to bind to oxygen and transport oxygen around the whole body.

What are the adaptations of a root hair cell?

The root hair cell has a long narrow extension which increases surface area to volume ratio which increases the rate of uptake of water and mineral salts in the cell.

What is the adaptation of a muscle cell?

A muscle cell has many mitochondria to produce energy for the cell for muscle contractions.

What is the relationship between surface area to volume ratio and the rate of diffusion?

As the surface area to volume ratio increases, the faster the rate of diffusion . However , as the surface area to volume ratio decreases, the slower the rate of diffusion is. The bigger a cell is , the slow are the rate of absorption of nutrients and mineral salts.

What is the function of carbohydrates?

Carbohydrates is a main energy source in the body for cell activities. Carbohydrates are needed to from supporting structures. Carbohydrates are needed to synthesize lubricants and nectar. Carbohydrates are also needed to form nucleic acids. Carbohydrates are also used for conversion into other organic compounds like amino acids and fats.

How are double sugars formed?

Double sugars are formed when two single sugars are joined together.

What is glycogen made out of?

Glycogen is made out of glucose and fructose.

What is cellulose made out of?

Maltose and Glucose

What are the functions of fats?

Fats act as an alternative energy source for the body. Fats also act as insulation to prevent heat loss from the body. Fats also act as a solvent for some fat-soluble vitamins and some hormones. Fats also are important for the formation of the main part of the cell membrane. Fats also help to reduce water loss from skin surface.

What do fats comprise of?

Fats are comprised of fatty acids and glycerol.

What are the functions of proteins?

Proteins are needed for the synthesis of new cytoplasm for growth and repair of worn-out body parts.; proteins are needed t=for the synthesis of enzymes and some hormones. Proteins are needed for the formation of antibodies to combat diseases.,

How do we conduct a Benedict’s test?

1. Pour 2 cm^3 of Benedict’s solution into a test tube.
2. Add 2 cm^3 of food sample in a test tube and shake the mixture.
3. Place the contents in a beaker of boiling water for 2 to 3 minutes.

How do we conduct a Biuret test?

1. Add 2cm^3 of biuret’s solution into the clean test tube.
2. Add 2cm^# of the food sample into the biuret’s solution
3. Shake well and then leave the solution to set for 5 minutes and record the observations