Biology- Topic 1/ Key concepts

Question 1

Eukaryotic cells have:

Answer 1

Membrane bound organelles such as a nucleus, mitochondria and ribisomes.

Question 2

Prokaryotic cells have:

Answer 2

No membrane bound organelles.

Question 3

Bacteria- DNA

Answer 3

One large loop of chromosomal DNA and smaller loops of plasmids

Question 4

Bacteria specialised

Answer 4

Additional capsule/slime layer and the flagellum tail to propel itself

Question 5

Nucleus

Answer 5

Controls activities of the cell and DNA

Question 6

Cytoplasm

Answer 6

Jelly like substance where chemical/ metabolic reactions take place

Question 7

Ribisomes

Answer 7

Protein synthesis

Question 8

Mitichondria

Answer 8

Where aerobic reactions take place (respiration and ATP)

Question 9

Cell membrane

Answer 9

Controls what enters and exits the cell, partially permeable

Question 10

Chloroplasts

Answer 10

Green dye that absorbs sunlight for photosynthesis

Question 11

Cell Wall- Plants

Answer 11

Made of cellulose is fully permeable and gives the plant structure

Question 12

Large Permanent Vacuole

Answer 12

Storage of sap and gives the plant structure

Question 13

How are sperm cells adapted to their functions?

Answer 13

Acrosome/ streamline shape- holds digestive enzymes.
Midpiece- Holds many Mitochondria for energy.
Flagellum- Swim to the egg.
Haploid nucleus- single set of chromosomes that contains to right information for the fetus growth.

Question 14

How are egg cells adapted to their functions?

Answer 14

Haploid nucleus- single set of chromosomes that contains to right information for the fetus growth.
Nutrients in cytoplasm- for the early growth of the fetus.
changes in cell membrane- only one sperm can enter

Question 15

How are ciliated cells adapted to their functions?

Answer 15

Many mitochondria to make cilia hairs move and woft micros and debris out of airways.

Question 16

Electron microscopes vs light microscopes

Answer 16

electron microscopes due to the shorter wavelength of electrons than light, produce images with higher resolution.

Question 17

Magnification calculation

Answer 17

Image= Magnification x actual size

Question 18

What do enzymes do?

Answer 18

Enzymes bind to substrates from their active site and speed up metabolism.

Question 19

How can enzymes be denatured?

Answer 19

Temperature- too much kinetic energy breaks enzymes intermolecular bonds.
pH- Presence of more h+ ions or OH- ions can change the active site
Substrate concentration- With more substrate than enzymes peak rate will be attained meaning the graph will be still.

Question 20

Rate

Answer 20

rate =
change/time

Question 21

How to test for starch?

Answer 21

Place iodine into wells on a dimple tile with food samples. Iodine will go from yellow- blue

Question 22

How to test for Protein?

Answer 22

Add buirite into wells on a dimple tile with food samples. It will go blue to purple

Question 23

How to test for sugar?

Answer 23

Place benedicks in a test tube with food samples and place in hot water bath for 5 minutes. Yellow-orange-red

Question 24

How does calorimetry measure energy in food?

Answer 24

By burning food in the combustion chamber use a thermometer to calculate the difference in temperature. Use the equation energy= ((final temp-start temp) x 4.2 x volume of water)/ mass of food

Question 25

How to calculate percentage change in osmosis

Answer 25

(Final mass- initial mass)/ initial mass
multiply by 100.