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Flashcards in Biology Deck (102)
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1

what is the cytoplasm ?

liquid gel which contains enzymes, where chemical reactions happen

2

what are mitochondria ?

structures where oxygen is used and energy is released during aerobic respiration

3

what is the function of the permanent vacuole ?

- stores cell sap
- provides rigidity and cell support

4

what is cell sap ?

weak solution of: salt, sugar, mineral ions, waste molecules

5

how are erythrocytes specialised ?

- haemoglobin
- biconcave shape
- anuclear (no nucleus)
- mature cells have no mitochondria

6

give advantages of biconcave shape of erythrocytes

- large SA
- can squeeze through capillaries

7

how are sperm cells specialised ?

- flagellum allows movement
- head is streamlined
- head is acrosome (contains digestive enzymes)
- middle packed with mitochondria

8

what do egg cells carry ?

female DNA and store food to provide energy / building molecules for early stages of developing embryo

9

what happens to cell membrane of egg once fused with sperm ?

strengthens to prevent other sperm from entering

10

give the total number of human chromosomes

46

11

how is genetic material contained in bacterial cells ?

free in cytoplasm (in rings - plasmid)

12

what is the term for bacteria division ?

binary fission

13

what do bacteria often produce that is harmful ?

toxins

14

give 3 ways in which white blood cells help defend the body

- ingest microorganisms
- produce antigens
- produce antitoxins

15

what are antitoxins ?

antibodies that neutralise toxins

16

how is antibiotic resistance avoided ?

- patients finish course of antibiotics
-medics avoid unnecessarily prescribing

17

what is the most common example of a 'super bug' ?

MRSA

18

what type of pathogen are antibiotics used for ?

bacteria

19

give 4 functions of proteins

- structural components (muscles/tendons)
- hormones
- antibodies
- enzymes

20

enzymes at high temp are described as ...

denatured

21

enzymes at low temp are described as ...

inactive

22

what is the optimum temp for most human enzymes ?

37 degrees Celsius

23

what is pepsin and what is its optimum pH?

stomach enzyme at a pH of 2 (acidic)

24

what does changing the pH do to enzymes ?

alters intermolecular forces and bonds that holds the enzyme, altering active site shape

25

where is bile produced ?

the liver

26

what is the function of bile ?

neutralises stomach acid and emulsifies fat

27

how is food broken down in the stomach ?

- mechanical digestion from muscular walls
- HCl produced gives opt. pH for pepsin to work and kills pathogens

28

function of pancreas (for digestive system)

releases enzymes into small intestine

29

function of large intestine

absorbs water and ions

30

function of small intestine

absorbs soluble food molecules