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Nat 5 Biology > Cells > Flashcards

Flashcards in Cells Deck (58)
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1

What is the third step of mitosis?

-nucleus membrane breakdown
- the chromosomes line up on equator of the cell

2

Why is the first step of mitosis?

DNA is tightly coiled in the nucleus

3

Explain the function of receptor enzymes

Cell identity tags

4

Describe the structure of the cell membrane?

Phospholipids make up the basic structure
And it's made up of protein and lipids(fat)

5

Name two facts about DNA?

- double stranded
- twisted into a double helix

6

Name the three parts of a nucleotide ?

Phosphate, deoxyribose sugar and base

7

What is DNA structure made up of?

Nucleotides

8

Name two parts of a chromosome?

Chromatids, centromere

9

Describe function of a cell wall?

Maintains cell shape/support

10

Describe function of chloroplasts?

Site of photosynthesis

11

Describe stage 5 of mitosis

- chromatids are pulled to opposite ends of the cell
-nuclear membranes formed
- two identical daughter cells are formed

12

Higher water concentration outside plant cell?(3 marks)

Higher water concentration outside cell, water moves into cell, cell=turgid

13

Same water concentration outside plant cell?

Water movement Is balanced

14

What is the second step of mitosis?

-chromosomes shorten and thicken
-chromosomes double to form two identical chromatids which join at a centromere

15

Lower water concentration outside plant cell?(3marks)

Higher water concentration in cell, water moves out cell, cell is plasmolysed

16

Higher water concentration outside animal cell?(2 marks)

Higher water concentration outside cell, water moves into cell, cells burgs

17

Explain"optimum" in terms of enzymes

Conditions enzymes work best at, usually body temp

18

State an enzyme equation

HP COW
Hydrogen peroxide ---------->oxygen and water
Catalase

19

Explain function of an antibody enzyme

Fight infections

20

Describe function of a hormone protein

Body messenger eg insulin

21

Explain function of enzyme protein

Speed up chemical reactions eg amylase

22

Explain how proteins have different shapes

They all have different jobs to do

23

Describe how DNA is carried to the ribosomes

By a messenger molecule called MRNA

24

Name the base pairs

A+T G+C

25

What does active transport require?

Energy

26

Describe process of active transport

The moment of molecules from a low concentration to a high concentration against a concentration gradient

27

What's the simple enzyme equation?

Substrates---------->product
Enzymes

28

Photosynthesis equation?

Sunlight
Co2 and water --------------> oxygen and glucose
Chlorophyll

29

Three things plants use glucose for

Respiration, stored as starch, makes cellulose

30

Three limiting factors of photosynthesis

Light intensity, carbon dioxide, temperature