Key Concepts - Year 10

Question 1

Animal Cells have….

Answer 1

Nucleus, cell membrane, cell wall, mitochondria and ribosomes

Question 2

Plant cells have…..

Answer 2

Nucleus, cell membrane, cell walls, chloroplasts, mitochondria, vacuole and Ribosomes

Question 3

Bacteria have….

Answer 3

Chromosomal DNA, plasmid DNA, cell membrane, ribosomes and flagella

Question 4

Sperm cells have an adapted to their function by….

Answer 4

Acrosome , haploid nucleus, mitochondria and tail

Question 5

Egg cells have an adapted to their function by….

Answer 5

Nutrients by the cytoplasm, haploid nucleus and changes in the cell membrane after fertilisation.

Question 6

Ciliated epithelial cells….

Answer 6

The hairs sweep hair, mucus, trapped dust and bacteria up to the back of the throat where it can be swallowed.

Question 7

How have microscopes enabled us to see cell structures??

Answer 7

They have been established and have been adapted so we can see closer

Question 8

The relationship between quantitive units are…

Answer 8

Milli - (10-3)
Micro - (10-6)
Nano - (10-9)
Pico - (10-12)

Question 9

Enzyme Action….

Answer 9

The basic mechanism by which enzymes catalyse chemical reactions begins with the binding of the substrates to the active site on the enzyme.

Question 10

Enzymes can be denatured by

Answer 10

Increasing the temperature to 60• will cause permanent change to the shape of he active site. This is why enzymes stop working when they are heated.

Question 11

The effects of temperature substrate concentration and PH enzyme activity are…

Answer 11

As the temperature increases, so does the rate of reaction. The enzyme activity gradually increases with the temperature up to around 37•, or body temperature

Question 12

Rate calculations for enzyme action…

Answer 12

The rate of a reaction can be calculated by multiplying the rate constant by the substrate concentration or by determining reaction reaction velocity

Question 13

What are he importance of enzymes??

Answer 13

They control the speed of chemical reactions in your body. Without enzymes, these reactions could take place too slowly to keep you alive.

Question 14

How can the energy contained in the food be measured using calorimetry?? Step 1

Answer 14

Poor cold water in to a boiling tube.

Question 15

How can the energy contained in the food be measured using calorimetry?? Step 2

Answer 15

Record the starting temperature of he water

Question 16

How can the energy contained in the food be measured using calorimetry?? Step 3

Answer 16

Record the mass of the food sample

Question 17

How can the energy contained in the food be measured using calorimetry?? Step 4

Answer 17

Heat he food until it catches fire

Question 18

How can the energy contained in the food be measured using calorimetry?? Step 5

Answer 18

Heat the water using the flame from the burning food

Question 19

How can the energy contained in the food be measured using calorimetry?? Step 6

Answer 19

Record the final temperature of the water

Question 20

How can the energy contained in the food be measured using calorimetry?? Equation

Answer 20

Energy transferred (J) = mass of water (g) x 4.2 (J/g•c) x temperature increase (•c)

Question 21

Diffusion….

Answer 21

Occurs when the partials spread. They move from a region where they are in high concentration to a region where there and low concentration.

Question 22

Osmosis…

Answer 22

Osmosis is the movement of water from a less concentrated solution to more concentrated through a partially permeable membrane

Question 23

Active transport…

Answer 23

The process by which dissolved molecules move across a cell membrane in from lower to higher concentration. They move against the concentration gradient.

Question 24

Percentage gain and loss of mass in osmosis

Answer 24

Percentage change in mass = (end in mass - start mass) / start mass x 100