Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

y3 biology > unit 2 bio (cells) > Flashcards

unit 2 bio (cells) Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards Biology 101 flashcards
1
Q

characteristics of eukaryotic cells

A
  • have a nucleus
  • contain membrane bound organelles
  • larger cell size
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

function of the nucleus

A

controls cell activities such as growth and the repair of worn out parts
contains chromosomes: long, thread-like structures made up of DNA which stores hereditary information
contains nuclear membrane: separates contents of nucleus from the rest of the cytoplasm; contains nuclear pores and has 2 layers of membranes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

function of cell surface membrane

A

partially permeable membrane made up of lipids and proteins
controls the movement of substances in and out of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

function of cytoplasm

A

jelly like substance that fills up the cell; site of cell activities and contains organelles that perform a specific job within the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

function of cellulose cell wall

A

protects cell from injury and gives the cell a fixed shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

function of rough endoplasmic reticulum

A

surface is studded with ribosomes which give it a rough appearance
modifies proteins made by ribosomes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

function of smooth endoplasmic reticulum

A

tubular, smooth, appearance due to absence of ribosomes attached to its surface
synthesises substances like fats and steroids and converts harmful substances into harmless substances through detoxification

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

function of ribosomes

A

synthesise proteins in the cell
ribosomes attached to RER make proteins that are usually transported out of the cell
ribosomes lying freely in cytoplasm make proteins that are used within the cytoplasm of the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

function of golgi body

A

cup shaped compartments known as cisternae
chemically modifies substances made by endoplasmic reticulum
stores and packages vesicles for secretion out of the cell or to other organelles in the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

process of secretion of substances in golgi body

A
  1. vesicles containing polypeptide made by RER pinch off from the RER
  2. vesicles fuse with golgi body and release the molecules made by the ER into it. the substances may be modified by the golgi body
  3. secretory vesicles containing modified substances pinch off from the golgi body and move towards the cell surface membrane
  4. secretory vesicles fuse with the cell surface membrane and their contents exit the cell
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

function of mitochondria

A

contains a double membrane that surrounds a matrix, inner membranes fold inwards to form cristae
site of aerobic respiration where food substances are broken down to release energy in the form of ATP, which may be used to perform activities such as cell growth and reproduction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

function of chloroplasts

A

double membranes enclose a fluid filled space called the stroma, and the 3rd inner membrane (thylakoid membrane) forms the thylakoid. stacked thylakoid is known as granum
contains chlorophyll necessary for photosynthesis to occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

function of vacuoles

A

fluid filled space enclosed by a partially permeable membrane
stores substances within a cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

plant cell vacuoles vs animal cell vacuoles

A

plant: large, central vacuole that contains cell sap consisting of sugars, mineral salts, and amino acids + serves as disposal of waste materials

animal: numerous small vacuoles that store water and food substances

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

adaptations of muscle cells

A
  1. contain many mitochondria: provide energy for contraction of muscle cells
  2. contain contractile protein fibres: fibres contract and relax to bring about movement
  3. contain many nuclei: allow for cell division
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

adaptations of root hair cells

A

long and narrow extension: increases surface area to volume ratio of cell for increased rate of absorption of water and mineral salts via osmosis and diffusion

low water potential in vacuole: allow for osmosis of water into cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

adaptations of red blood cells

A

biconcave shape: increase surface area to volume ratio of the cell for increased rate of oxygen uptake
flexible: allows cells to squeeze through narrow blood capillaries easily
contains haemoglobin: binds to oxygen easily to transport it around the body
no nucleus: to contain more haemoglobin to transport more oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

definition of diffusion

A

net movement of particles from a region of higher concentration to a region of lower concentration down a concentration gradient

19
Q

what is facilitated diffusion

A

diffusion of substances through cell membranes using specific protein channels or carriers from regions of higher concentration to regions of lower concentration
- carrier mediated: via protein carrier
- channel mediated: through a protein channel, mostly ions

20
Q

factors affecting rate of diffusion

A

concentration gradient
diffusion distance
surface area to volume ratio

21
Q

definition of osmosis

A

net movement of water molecules from a region of higher water potential to a region of lower water potential through a partially/selectively permeable membrane down a water potential gradient

22
Q

effects of high water potential on plant cells

A
  1. cell sap in vacuole has lower water potential than surrounding solution
  2. net movement of water molecules into the cell via osmosis
  3. cell expands and becomes turgid
  4. cell wall prevents cell from bursting as cytoplasm volume increases
23
Q

effect of low water potential on plant cells

A
  1. cell sap in vacuole has higher water potential than surrounding solution
  2. net movement of water molecules out the cell via osmosis
  3. cell becomes flaccid and limp
  4. vacuole decreases in size, cytoplasm shrinks away from cellulose cell wall, cell surface membrane pulls away from cell wall and becomes plasmolysed
24
Q

effect of high water potential on animal cells

A
  1. cytoplasm has lower water potential than surrounding solution
  2. net movement of water molecules into the cell via osmosis
  3. cell expands and bursts
25
Q

effect of low water potential on animal cells

A
  1. cytoplasm has higher water potential than surrounding solution
  2. net movement of water molecules out of the cell via osmosis
  3. cell shrinks in size and becomes crenated
26
Q

definition of active transport

A

the process in which cellular energy in the form of ATP is used to move the particles of a substance from a region of lower concentration to a region of higher concentration across a membrane against a concentration gradient

27
Q

chemical composition of proteins

A
  • made up of carbon, hydrogen, oxygen, nitrogen, and sulfur
  • contain a basic amino group (NH2), an acidic carboxyl group (-COOH), and a variable R-group
  • general formula: R-CH-NH2-COOH
28
Q

function of proteins

A
  • growth and repair of worn out body cells
  • synthesis of new cytoplasm
  • synthesis of enzymes, hormones, and antibodies to combat diseases
29
Q

levels of organisation of proteins

A

primary structure: unique number and sequence of amino acids held together by peptide bonds that make up a polypeptide chain
secondary structure: folding and coiling of parts of the polypeptide to form alpha helices or beta-pleated sheets
tertiary structure: overall unique 3d structure of the polypeptide held together by hydrogen, ionic, disulfide bonds and hydrophobic interactions
quarternary structure: when two or more polypeptide chains join together to form a biologically functional protein

30
Q

chemical composition of carbohydrates

A

contain carbon, hydrogen, and oxygen atoms (h and o atoms present in 2:1 ratio)
general formula: Cx(H2O)y

31
Q

functions of carbohydrates

A
  • used as substrate for respiration to provide energy for cell activities
  • to form supporting structures
  • for formation of nucleic acids
32
Q

name monosaccharides

A

glucose, galactose, fructose

33
Q

name disaccharides

A

maltose, lactose, sucrose

34
Q

name polysaccharides

A

glycogen, starch, cellulose

35
Q

chemical composition of fats

A

made up of carbon, hydrogen, and oxygen
no general formula

36
Q

functions of fats

A
  • long-term storage of energy
  • insulating and prevents excessive heat loss
  • solvent for fat soluble vitamins and other vital substances
  • reduces water loss from skin surface when oils form a layer over it
37
Q

what are enzymes

A

biological catalysts that speed up the rate of a chemical reaction and remain chemically unchanged at the end of the reaction

38
Q

characteristics of enzymes

A
  • speed up the rate of chemical reactions by lowering the activation energy needed to start the reaction
  • specific in action
39
Q

factors affecting efficiency of enzymes

A

temperature
pH

40
Q

how does low temperature affect enzymes

A

kinetic energy of molecules is low, hence enzyme and substrate molecules move slowly. there is a decrease in the rate of collisions between enzyme and substrate molecules, less enzyme substrate complexes are formed

41
Q

how does high temperature affect enzymes

A

high temperatures break the bonds that keep enzymes in their specific shape. their active sites lose their original shape and are no longer complementary to the substrate. enzymes become denatured and lose their catalytic function

42
Q

how does change in pH affect enzymes

A

changes in pH alter the shape of the active sites of the enzyme, causing active sites to lose their original shape. active sites are no longer complementary to the substrate, and enzyme-substrate complexes cannot be formed. the enzyme is denatured and lose their catalytic function

43
Q

process of enzyme breaking down substrate

A
  1. upon effective collisions between the substrate and the active site of the enzyme, an enzyme-substrate complex is formed
  2. reactions take place at the active site to convert substrate molecules into product molecules
  3. products separate from the enzyme which remains unchanged and is free to bind with more substrate molecules
  4. when reaction is completed, products no longer fit into the active site of the enzyme

y3 biology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions