Brainscape's Knowledge GenomeTM

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


See full index

Biology🧬 > Exchange > Flashcards

Exchange Flashcards

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

How would you work out the Surface Area : Volume ratio?

A
  1. Work out surface area: length x width x number of sides
  2. Work out volume: length x width x height
  3. Do surface area divided by volume
  4. Ans:1
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What type of SA:V ratio do large and small animals have?

A

Small: have a high ratio, e.g a mouse is 6:1

Large: have a low ratio, e.g hippo is 2:1

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

How are single-celled organisms different to multicellular organisms withy SA:V ratio?

A

In a singular celled organism substances can diffuse directly in and out of the cell- it is quick because of the short diffusion pathway.

However, in multicellular organisms diffusion would be too slow as we have cells deep within our body so a large distance and a low SA:V ratio, so we need exchange organs and mass transport systems.

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

How might it be better for animals to adapt to aid exchange?

A

Size: if an animal is larger it has a lower SA:V ratio, so it is harder to lose heat, opposite for smaller animals, so they have to have a high metabolic rate to generate enough heat.

Shape: animals with a compact shape (e.g round head) have low SA:V, minimising heat loss, whereas more sticky out features with a large SA:V increase heat loss.

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

Why can’t insects take in water and gases through their exoskeleton?

A

The exoskeleton (chitin) is impermeable to water, oxygen , and carbon dioxide, for gas exchange occurs through pores in the body surface.

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

What is the structure of an insects gas exchange system?

A

-Has pore openings in the body surface called spiracles.
-Tubes called tracheae and tracheoles extend the spiracles into the body’s tissues.
-Rings of chitin prevent collapse when the air pressure inside the tracheae is less than atmospheric pressure.

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

How has the insects gas exchange system adapted to reduce water loss and gain sufficient oxygen?

A

-Spiracles have valves that open and close to prevent water loss.
-Spiracles have tiny hairs for dust filters.
-Lots of tracheoles that are one cell thick for a short diffusion distance.
-High surface area

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

How does an insects tracheal system work?

A
  • A solution of gases and other substances fill the ends of the tracheoles.
  • Oxygen and carbon dioxide are exchanged between the solution filling the ends of the tracheoles and cells of tissues nearby.
  • Oxygen is supplied to tissues, CO2 is removed. (going down their conc gradients)

They use Rhythmic abdominal movements to move air in and out of the spiracles.

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

What type of circulatory system do fish have?

A

Single circulatory system where blood flows through the heart once for each circuit of the body.

Heart > Gills > Body > Heart

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

Describe the structure of gas exchange in a fish

A
  • Bone called a gill arch
  • Filament project from the Gill arch
  • Lamellae are folds on the filaments
  • Operculum is a flap which cover the gill slits
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the benefit of a countercurrent in a bony fish?

A

The water and their blood flows in opposite directions.

This means that a concentration gradient of oxygen from the water into the bloodstream can always be maintained, as it diffuses from high to low, along the length of the filament.

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

What are the adaptations of that gas exchange system in a bony fish?

A
  • Filaments provide a large surface area
  • Lamellae provide an even bigger surface area as they are folded
  • Countercurrent maintains conc gradient, maximising diffusion
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the respiratory current (fish)?

A

The flow of water through the mouth and over the lamellae- there is a continuous flow of water over the lamellae.

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

What is ‘Inspiration’ (fish)?

A

-Lowering the floor of the pharynx (mouth, bottom lip) increases the vol of the mouth cavity and reduces pressure.
-Water flows in through the open mouth and over the lamellae.

(ventilation)

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

What is ‘Expiration’ (fish)?

A

-Raising the floor of the pharynx (mouth, top lip) reduces the volume of the mouth cavity and increases pressure.
-The pressure pump effect pushes water over the lamellae and against the opercula, pressing them open.
-So water is able to leave the fish.

(ventilation)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Name everything in the cross section of a leaf, and their function

A

Waxy cuticle: prevents evapouration of water

Upper/lower epidermis: prevents pathogens getting in, transparent

Palisade mesophyll: contains tightly packed chloroplasts for photosynthesis

Spongy Mesophyll: air spaces for gas exchange/circulation

Vascular bundle: contains xylem and phloem for transpiration and translocation

Stomata: pores for gas exchange and transpiration

Guard cells: open and close for gas exchange

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

What are some factors effecting gas exchange in plants?

A

-Increased temp
-Decrease humidity
-Increase wind
-Increase light intensity

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

What is the ‘Compensation Point’ in a leaf?

A

when the conc of CO2 produced in aerobic respiration balances that used in photosynthesis, then the net exchange of CO2 between the leaf and the atmosphere is zero.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What does Xerophytic mean?

A

Plants that are able to survive in hot, dry conditions.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How does stomata open and close?

A
  • Guard cells fill with water and become turgid, and push apart. this is because there active transport of K+ ions into the cells from surrounding cells, so the guard cells now have water potential of guard cells becomes negative, water passes in via osmosis.
  • Active transport of K+ ions is activated by light and photosynthesis, therefore the whole of the above process is reversed, stomata closes.
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Name the features of the human gas exchange system and their function

A

Nasal cavity: is moist to dissolve gas, has hairs to trap microorganisms, warms up the air

> Pharynx and larynx

Trachea: Route to lungs, has ‘C’ rings of cartilage for support and flexibility.

Bronchus: same as trachea but smaller.

Bronchioles: has a layer of muscle that can contract and relax to control air flow.

Alveoli: One cell thick , flattened epithelial cells, good blood supply as wrapped in capillaries, lined with collagen and elastic fibres so the don’t break under air pressure.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens to our body during inhalation?

A

-Diaphragm contracts and flattens, increasing volume
-External intercostal muscles contact, internal relax
-Therefore the ribcage moves up and out
-Volume of the thorax (chest) increases, pressure decreases
-Air is drawn in

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens to our body during exhalation?

A

-Diaphragm relaxes and becomes dome shaped
-External intercostal muscles relax, internal contract
-Ribcage moves down and in
-Volume of thorax (chest) decreases, pressure increases
-Air is forced out

24
Q

Talk about the atmospheric pressure in terms of inhalation and exhalation

A

Inhalation: want the atmospheric pressure to be lower inside the lungs and higher outside so that air can move from a high to low conc (into the lungs)

Exhalation: Atmospheric pressure to be higher inside than outside the lungs, for a conc gradient, loss of air.

25
Q

What is the pleural cavity and what is its function?

A

The space between the lungs and the ribcage. Lubricated membranes for easier movement of the lungs.

26
Q

How do insects reduce water loss?

A

-Small surface areas to volume ratio
-Exoskeleton is impermeable
-Control opening and closing of spiracles (CO2 conc)

27
Q

Why do larger organisms need specialised gas exchange systems?

A

The diffusion distance is too large from the surface to cells, so specialised gas exchange surfaces with an increased surface area reduce the distance.

28
Q

How could you find out where and how many stomata there are on a plant leaf? (bit of a weird one)

A

-Use clear nail varnish to coat the underside of the leaf, leave to dry and peel away.
-Place under a light microscope and count the presence of guard cells

29
Q

Apart from gases, what other dissolved substances are exchanged in fish?

A

Ions and the regulation of pH is managed by the gills.

30
Q

What are the adaptations of a dicotyledonous leaf for diffusion?

A

-Thin leaves
-Air spaces, increases Sa:V
- Stomata

31
Q

What is Carbohydrase?

A

An enzyme that catalyses the digestion of carbohydrates such as starch into simple sugars.

32
Q

What is Protease?

A

An enzyme that catalyses the digestion of protein into amino acids.

33
Q

What is Lipase?

A

An enzyme that catalyses the digestion of triglycerides into fatty acids and glycerol.
-Breaks ester bonds
-Made in the pancreas, released into the small intestine.

34
Q

Where can carbohydrases be found and how do they work?

A

-Saliva in the mouth contains amylase, catalysing the hydrolysis of starch into maltase (chloride ions activate the amylase).

-The duodenum receives pancreatic juice from the pancreas that also contains amylase.

35
Q

What is a disaccharidase?

A

Specific enzymes that are secreted by the epithelial cells of the intestinal wall, that hydrolyse specific disaccharides.
e.g maltose, sucrose, lactose

(glycosidic bonds)

36
Q

Name the 3 disaccharidases and their function

A

-Maltase: (catalyses the hydrolysis of) maltose tho glucose

-Sucrase: () sucrose to glucose and fructose

-Lactase: () lactose to glucose and galactose

37
Q

What is a Dipeptidase?

A

An enzyme that catalyses the hydrolysis of the peptide bond joining the pairs of amino acids forming dipeptides- amino acids released.

(Proteins)

38
Q

What is an Endopeptidase?

A

-An enzyme that catalyses the hydrolysis of of the peptide bonds within protein molecules
-Broken down into smaller molecules of polypeptides or peptides.
-Found in the gastric and pancreatic juice, secreted by the cells of the small intestine.

(Protein)

39
Q

What is an Exopeptidase?

A

-An enzyme that catalyses the hydrolysis of peptide bonds linking the amino acids at each end of the polypeptide/peptide chain.
-Amino acids released, chain shortens until a dipeptide.
-Found in the pancreatic juice and secreted by the small intestine

(Protein)

40
Q

Where is bile made, stored, and released?

A

Made: Liver
Stored: Gall bladder
Released: Duodenum

41
Q

What is Emulsification of a lipid?

A

Breaks up lipids into tiny droplets called micelles, which increase the surface area to which the lipase can react.

42
Q

What emulsifies lipids?

A

Bile salts in bile juice

43
Q

What is protease in the stomach called?

A

Pepsin

44
Q

How is the surface area of the small intestine increased?

A

-The wall has folds called villi, so increases the rate of absorption.
-The surface of the epithelial cells lining villi also have small folds called microvilli.

45
Q

Where are monosaccharides and amino acids absorbed?

A

Begins in the duodenum, but most occur across the wall of the ileum.

46
Q

Describe the passage of monosaccharides and amino acids into the bloodstream

A

-Passes through the plasma membrane of each epithelial cell
-Across each cell
-Through the opposite side of each cell
-Through the plasma membrane of the cells of the wall of a capillary blood vessel.

47
Q

Describe the structure of the capillary network in villus

A

There is a network of capillary blood vessels and lacteal vessels in each villus that run to the hepatic portal vein and into the lymphatic system.

48
Q

Explain how co-transport is used to transport monosaccharides and amino acids across the plasma membrane

A

-Sodium ions are actively transported out of the cell and into the bloodstream, creating a conc gradient for sodium ions to move from the lumen to the cell via facilitated diffusion. This is done by the sodium potassium pump, using ATP.

-As the sodium ions are transported in, glucose or amino acids move into the cell at the same time, using a carrier protein.

-Now the conc is higher for glucose/amino acid in the epithelial cell and can diffuse down the conc gradient into the bloodstream, using facilitated diffusion and a carrier protein.

49
Q

Explain how glycerides and fatty acids are absorbed, through the plasma membrane

A

-They combine with bile salts and then emulsify to micelles.

-Micelles are delivered to the surface of the epithelial villi cells, via movement of the lumen.

-Micelles breakdown, releasing their contents for diffusion into the villi.

-Vitamins A and D, and cholesterol are also transported there by micelles.

-Within the villus cells, triglycerides are re-esterified on the smooth endoplasmic reticulum from fatty acids and monoglycerides, then transported to the golgi apparatus.

-In the golgi apparatus, triglycerides are modified and combined with proteins. They are packaged in an envelope of protein, cholesterol, and phospholipids, called Chlomicrons, that pass out via exocytosis.

-They circulate in lymph of the lymphatic vessels, and drain into the left subclavian vein via the thoracic duct.

50
Q

Monosaccharides and amino acids pass into the hepatic portal vein to be transported in the blood stream- to go where?

A

The liver

51
Q

What is the role of bile?

A

-Neutralises excess stomach acid in the duodenum
-Emulsifies fats
-Optimum pH for enzymes

52
Q

What is the Alimentary Canal?

A

All the parts of the body where food passes through mouth to rectum; everything else is an accessory (e.g liver).

53
Q

What 3 parts make up the small intestine and what order are they in?

A

1.Duodenum
2.Jejunum
3.Ileum

54
Q

What do micelles contain?

A

Bile salts
Fatty acids
Monoglycerides/glycerol

55
Q

What is the role of micelles?

A

-Make fatty acids more soluble in water
-Maintain a high conc of fatty acids to the cells lining the ileum.
-Carry fatty acids and glycerol to the cell.

Biology🧬 (10 decks)

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