Biology

Question 1

What are enzymes? Their function?

Answer 1

Enzymes are protein made up of monomers called amino acid. They are biological catalyst that speed up the rate of cellular reactions, but are not change by the process.

Question 2

What will happen if we did not have enzymes?

Answer 2

Without enzymes reactions are too slow to cure that the cells would die from not being able to do key life processes

Question 3

What happen if the temp gets to high for enzymes?

Answer 3

When they reach a high enough temperature, they will lose their shape and breakdown. Just as known as denaturation. the enzyme is then unable to function as the active site is the wrong shape for the substrate.

Question 4

What happen to enzymes in PH

Answer 4

The Ph level causes the enzymes active site to become denatured and the active site loses its important shape.

Question 5

Enzyme action

Answer 5

An enzyme usually only act on single specific reacting a.k.a. the substrate. They have a pocket or groove structure called the active site, its shape is complementary of the substrate. The enzymes can’t be consumed or altered.

Question 6

Define osmosis

Answer 6

Osmosis is the movement of water molecules from an area of high water potential to a area of lower water potential through a partially permeable membrane.

Question 7

What are solutes?

Answer 7

Solutes are substances that can be dissolved in a solvent (usually water)
Solute + solvent = solution

Question 8

Osmosis - turgor pressure

Answer 8

Turgor pressure is the force within the cell that pushes the cell membrane against the cell wall. Turgor pressure is important so that plants stay upright and have exposure to sunlight.

Question 9

Define hypertonic

Answer 9

A hypertonic solution is one that has a higher solute concentration than the cell.

Question 10

Define hypotonic

Answer 10

A hypotonic solution is one that has a lower solute concentration than the cell

Question 11

Define isotonic

Answer 11

An isotonic solution has a equal concentration of solutes inside and outside the cell.

Question 12

Plants cell in a hypertonic solution

Answer 12

When a plant cell is placed in a hypertonic solution, there is a movement of water out of the south, causing a reduction in turgor pressure and the cell membrane to peel back from the shower wall. This is known as the cell becoming plasmolysed.

Question 13

Plant cell in hypotonic solution

Answer 13

If a cell is placed in a hypotonic solution, there is a movement of water into the cell, causing an increase in turgor pressure and a cell to become turgid. The cell membrane pushes against the cell wall.

Question 14

Plant cells in an isotonic solution

Answer 14

If a cell is placed an isotonic solution, there is no movement of water, causing the cell to stay the same.

Question 15

What is glucose? Their function?

Answer 15

A glucose molecule is made from carbon, hydrogen and oxygen. The glucose function is to produce energy from respiration. Plants transport sucrose, which is then converted into glucose and use for respiration.

Question 16

What are the tree functions of glucose? Their function?

Answer 16

All of these are made from chains of glucose
* cellulose - plants used to make cell walls
* starch - plants used to store energy
* glycogen - animals, use to store, energy in liver

Question 17

Testing for reducing sugar

Answer 17

We can test for reducing sugars using Benedict solution
When it is heated, it turns:
Blue - green - yellow - orange - red

Question 18

Testing for starch

Answer 18

We can test for starch by using iodine
It turns orange/brown - blue/black

Question 19

What is the fat structure?

Answer 19

Contains carbon hydrogen oxygen
Three Fatty acid chains joint to one.glycerol molecule

Question 20

Detail of fats

Answer 20

Solid fats room temperature contain situated fats and liquid fat known as oils contain unsaturated fats.

Question 21

Function of fats

Answer 21

Energy dense molecule, factor under skin is adipose tissue that insulates the body, used to produce cell membranes and some hormones, plants store oil in their seeds

Question 22

Testing for fats

Answer 22

The ethanol emulsion test. If fat is present the solution will turn cloudy.

Question 23

Structure of proteins

Answer 23

Proteins are made of long chains of amino acid molecules and they are made from hydrogen nitrogen oxygen, carbon and sometimes Sulfur.

Question 24

Function of amino acid?

Answer 24

Used to make new proteins and enzymes
Used for growth and repair cells
Used to make antibodies which are used to kill bacteria and viruses

Question 25

Testing for proteins

Answer 25

The biuret test. If protein is present it turns
blue - purple

Question 27

Define active transport

Answer 27

The movement of particles through a cell membrane from a region of lower concentration to a region of high concentration, using energy from respiration. Uses ATP as an energy source and requires a carrier protein in the cell membrane.

Question 28

Active transport in root hair cell

Answer 28

Plants need ions to survive e.g nitrate, potassium, magnesium, sodium, phosphates. Ions are in a lower concentration in the soil. Then they are in the root hair cells therefore, for the plant to get enough ions they are forced to use active transport to uptake more ions

Question 29

Structure of DNA

Answer 29

The structure of DNA is a double helix, the backbone is made of sugar and phosphate. The bases determine the code of DNA and are found on the inside of the double helix and bases held together by hydrogen bonds

Question 30

Base sequencing

Answer 30

T binds with A and C binds with G.
This make sure that we have a complimentary code on the second strand that we can use as the back up

Question 31

Define diffusion

Answer 31

Diffusion is the net movement of particles from our region of high concentration. Region of low concentration requiring no energy at all. (Passive transport)

Question 32

Which states are particles able to diffuse

Answer 32

Molecules in liquid and gases are constantly moving randomly and bumping into each other. This means that they tend to spread. In solids, the particle cannot move so diffusion does not occur.

Question 33

Factors that affect rate of diffusion - concentraction gradient

Answer 33

The difference in concentration between two areas is called a concentration gradient
Larger concentration gradient faster diffusion.

Question 34

Factors that affect rate of diffusion - temp

Answer 34

Temperature, more energy associated with the particle at high temperature means faster rate of diffusion

Question 35

Factors that affect the rate of diffusion - suface area

Answer 35

The larger the surface area in contact between the two regions, the faster rate of diffusion

Question 36

Factors that affect the rate of diffusion - distance

Answer 36

Distance the largest distance, the long time to diffuse

Question 37

Plasma membrane

Answer 37

Plasma membranes around cells/organelles, are semi permeable, meaning they allow some substances through, but not others

Question 38

Why is the diffusion important?

Answer 38

All living cells rely on the fusion to live they use it for:
* getting warm materials for respiration of photosynthesis
* removing waste product
* importing, or exporting products like protein